He was a busy man, and these seemed to be prosaic government documents, albeit framed. He cut off all the borders, stuck them onto Masonite and chipboard, slicked them over with wallpaper paste and sent them back. What else was a senior conservator at a major art gallery to do?

One could almost forgive him, if said drawings didn't happen to be the winning designs of what would become the nation's capital.

Today, they're not only the beautiful, evocative renderings of a fully realised city that would capture the imaginations of the panel appointed to judge the international entries for the design of Canberra. Walter and Marion Griffin, who together dreamed up the city's design, have themselves become the stuff of legend, and their ambitious plans the subject of painstaking conservation work in the physical sense, as well as through documentation and analysis.

And, if you're a multi-connected individual in the year 2013, the Griffins are ripe for a digital forum.

After all, it's not hard to imagine the dynamic duo, if they were still around, embracing the tablet and all its possibilities as they travelled the world and imagined alternative living spaces. Viewing the plans today with an extra layering of information - photographs, film, audio and documents - seems oddly appropriate in this era of the compulsive pinch-and-zoom.

The National Archive of Australia, which holds the plans in its collection, had long planned to use the Centenary year as an excuse to put the Griffin designs on display together for the first time. Design 29: Creating a Capital, opens this week, complete with customised iPads provided by the archives that give a whole new dimension to the now-famous watercolour renderings and graceful axes.

The show's title is a reminder of the sheer number of entries that came pouring in after the Federal Capital Design Competition was announced. By the time the competition closed, in February 1912, 137 entries had been received. To ensure the competition was fair, the judges gave each entry a number instead of naming the designers; the Griffins were number 29.

Exhibition curator Jane Macknight says the show is also a chance to display the winning entry alongside the runners-up - a chance for us to wonder how the city could have turned out if a different entry was chosen. As the story goes, back in 1912, the Board of Judges was unable to reach a consensus, and produced two separate reports: the Majority Report, which gave first place to Griffin (Marion barely registered as a separate entity back then), second to Eliel Saarinen, of Finland, and third to D. Alfred Agache, of France. The Minority Report (which lost out) gave first ranking to an Australian group, Coulter, Caswell and Griffiths.

Macknight likes to call the subjects of this Minority Report the "de facto fourth-place holder".

"I thought it would be great to put them all on display," she says.

"One of the wonderful things about seeing them in the flesh is that because of the sheer size of many of them, looking at them in digital format, you can't really get a good appreciation of them."

The Griffin works are especially large. Eight of the works form two four-part elevations that were originally hinged like a Japanese screen. "They'd been stored and they were reframed as separate works, so one of the things that we wanted to do for this exhibition is frame them back together," Macknight says.

In fact, by the time the Very Senior Conservator at the Art Gallery of NSW had finished with the odd little drawings he had been sent, they had already suffered more than enough indignities. The winning Griffin works, along with those of the other finalists, were, after all, just government documents back in Canberra's infancy. Having made it across the ocean by ship in time to be chosen as the design for the capital, they were then handled and punctured and rolled and packed into crates and stored in a Department of Works workshed in Kingston, where they remained, forgotten, until 1953. Realising they were worth preserving, the National Library took them into its custody, describing their condition as "good", and in 1957, the drawings were shifted to filing cabinets in a Nissen hut - no climate control there - in Parkes, ACT.

It was around this time that they were sent off to the Art Gallery of NSW for "treatment", a process conservators at the National Archives of Australia have spent the past two decades rectifying.

It would be too easy to put the shoddy treatment down to a lack of resources, or technology, or different philosophies about conservation work. But actually, says archives senior conservator Ian Batterham, the drawings were treated badly because no one cared. "They were in a bad state for a lot of reasons. They were not treated very well for many years, no one really cared about them, they were stored badly," he says. "There was a time, when it came to the history of Canberra, no one really cared. It was very sad. This sort of exemplifies it."

He began working on them in the 1980s and 1990s, and says each drawing took about three months to restore, although none were damaged beyond repair.

"The work I did was more just undoing that. Each one had to be split off the chipboard, cleaned because they were filthy, they were covered in black soot," he says.

"Some of them were damaged quite badly. A lot of the gilding had fallen off, there were puncture holes, but a lot of that was much earlier, in the 1920s."

Of course, today we accept them as priceless works of art, and the hands behind them - the enigmatic Chicago double act - have risen, posthumously, to become cult figures in the architecture world. Macknight says the plans, although they date back 100 years, are perfect fodder for the archive in the digital age.

"The thing with the exhibition is that rather than present an authoritative voice about why the Griffins are so good and why they're so important, we thought we'd put the Griffins up with the other finalists and give people a set of tools with which they can explore the different ideas for Canberra themselves," she says.

"And along the way we wanted to explore this whole idea of Canberra as an embodiment of nationhood. That was something that was conceived a long time before Canberra … was named in 1913."

The iPad experience, she says, is about giving a sense of place to Canberra today.

"We've also done things where you can layer across an aerial map of contemporary Canberra, so you can then think about the design that you're looking at from one of the finalists and how that relates to today," she says.

"Rather than tell people what we think, using the iPad technology to allow content to unfold, we try to present different ways that people can travel through their own story and explore things."

In the case of the very detailed European styles of the other finalists, this layering of interpretations can give an entirely different perspective on designing a not-yet-existent city.

And, best of all, visitors will have the benefit of the famous "key" - the long-lost and recently discovered accompanying document that goes with the Griffins' summit view from Mount Ainslie. The document, long thought to be missing, was uncovered in 2011, but is too fragile to be displayed. But thanks to the wonders of digital technology, can be called up instantly on the iPad, to be used, more or less, as intended.

"We're really putting ourselves out there using this technology," Macknight says.

"It will be a really new thing for a lot of our core audience, but we're really hoping that people engage with it, because it really does add a whole extra layer and depth to the exhibition."

From chipboard and wallpaper paste to the complete virtual experience - Design 29 has taken 100 years to end up where it belonged.

■ Design 29: Creating a Capital opens on March 1 at the National Archives of Australia and runs until September 8.