As a matter of theory, George's comment pretty much covers it:
Restoration is a word representing an idea. The idea is that a bike is being brought back to an original or previous condition. But this idea doesn't mean, per force, that the bike needs repainting. -- George
George Hollenberg MD CT, USA
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In practice, it strikes me that, for a concours or other competitive event, ideally, there would be a specific definition of "restoration" and a requirement for entry would be some detailed *before* pictures. Maybe it would make sense to look at what they do in major automobile concours in this area. Because from where I sit, restoration does not necessarily involve a repaint--unless the rules specified it...it might involve some very elaborate, and careful hand-touch-up of the original finish, for instance, but not a full repaint. Not to mention complete restoration on the parts-group side, which sometimes involves years worth of searching for just the right thing.
Purely personal opinion here, but for me a winning restoration would be indistinguishable from a bicycle that was original in every particular (compared to all competitors). The closer the restoration comes, by whatever means, to a bike that could be mistaken for original, is a winner. So, you'd look for as-original spokes, nipples, cables, rims, cable-casing, bar-tape, tires, all small hardware. It's gotta be *exactly* the same as when it came out of the maker's shop, or out of the bike-shop that built it up back in the day--or plausibly so, anyway, where no exact documentation is available.
Which is why, ideally, in a restoration competition, there would be two groups of photos: the bike as it was before the restoration began, and pictures of a completely original bike from the day.
Whether or not the bike has been repainted would be relevant only insofar as that repaint gets the bike closer to as-original condition and appearance.
And then there's the question of whether you're judging a restoration to as-new condition, or if you're allowing a certain degree of patina--that is, the bike can look used to the extent any self-respecting owner back in the day would have tolerated---try defining that though! <g> just a little subjective, yes?.
It seems to me winners in restoration categories should be setting an example for the most valued, or most entertaining or most educational (or a combination of all three) sort of restoration. To me, that's totally, fanatically original. To others, of course, other details--not original--would be the most valued. But fanatically original bikes generally command the most on the market too, and are most coveted by expert collectors--me, I'm still learning, but collectors and riders I respect hold bikes like these in the highest regard, topped only by a bike that is, in fact, totally original and not restored in any significant way.
It's a slippery slope, no doubt. A concise set of rules would sure help in judging a competition. We usually seat-of-the-pants this stuff, and inevitably there are complaints.
Charles Andrews Los Angeles
"everyone has elites; the important thing is to change them from time to time."
--Joseph Schumpeter, via Simon Johnson