Thanks for the advice all. Barring specific problems with the frame (and I'm having a local mechanic recommended by a knowledgeable friend look at that - fingers crossed - though I'll have to check out the resources mentioned, as I'm interested in getting more savvy on these kinds of things), I'm at least not concerned about suitability in terms of size/geometry - my favourite ride ever was an extremely similar CroMo Kawamura frame, in exactly the same size (the black Norco linked in the pics posed initially). This is, in effect, my much-improved replacement for that bike, which I had to sell 5000km from where I've landed (though I'll have to do without the Arabesque - which would suit this one less well in any case).
It will be a mix of old & new, components-wise: decided today on a new Shimano 105 crankset along with the wheels my recommended LBS mechanic will be building up from 105 hubs (still deciding between two different rims). This on top of the used, slightly scratched, but very functional Cinelli bar/stem added a little while ago, used 105 SLR levers, and the new (and very modern) Shimano R650 brakes I got in NYC recently as a take-off from a new bike they'd recently sold. Just picked up a set of 80s NOS MKS AR-2 pedals on ebay today for only a hair more than they'd be for the modern versions at the LBS...so all I'm really looking for is the derailleurs, and I'm thinking of trying to pick up some Suntour Cyclone (maybe a Superbe FD) to restore the original setup in this regard at least - and to match the Suntour shifters I started out with.
Even if there's some trouble that puts me in the hunt for another frame (and I'm pretty optimistic - though now, I think, a little more cautious about such things in general), I've put together practically everything I need to get a really nice ride out on the road...
Might be a little while as I get the wheels built and sort out a few non-bike-related projects, but I'll be sure to keep everyone informed when it starts coming together - pictures and a full report to come!