All those old parts have some sentimental value, just because they are still present and seem to be basically functional. The Avocet BB (it should be an Avocet because it was said they had yet another unique square-taper design) is a known high-quality design, at least I have a NOS set I installed and then pulled because I set up a bike then decided to sell the bare frame/fork, but it was an easy installation and a very smooth spinner, easily the match for my 1980 Masi BB from when I rebuilt her. I found the Avocet BB and chainset precisely fit an English lightweight frame I was setting up.

I'm also a big fan of Duopars and the Huret front mechs. Looking at your three Duopar pictures, it all looks normal, if I assume the chain was on the granny in your first pic. For the other two pics that is the correct shape for the cage with the big ring and the big rear cog engaged. I would limit your restoration to some cleaning with a toothbrush, moving everything with your handj to see how the springs and pivots work together, oil drops on the pivot points, work it some more by hand, and then reinstall it for riding. If it shifts ok after all that I think there's no need for further overhaul.

Main fragility on a Duopar rear is if you spin the crank pedalling backwards when the derailleur cage is not carefully feathered onto the selected rear cog - if the chain hangs up, your feet have the power to cause damage. If you still have that skill from the old days, you need now to use it.

I had an Italian fork straightened or otherwise remade at Cyclery North in the late 1970s - somebody had borrowed the bike and brought it back with the fork blades bent back, but no sign of fork damage - suspicious? But in any case somebody at the shop rectified the problem and restored the paint. I don't know who the mech was nor what the repair work was, but it cast me $75, putting a hurt on my university expenses back then! I think I saw Dwight Safter there from time to time, but don't think it was his work. I can't say I knew Eddie. Biiiig tall kid with long hair!

I tried to estimate your frame angles by measuring your photos with a protractor. The only thing I can say with confidence is that your seat tube angle is on the shallow side, like my 1952 Rudge sport bike, which has been pictured on this site. Your head tube is much steeper than mine. I don't believe the numbers I got, which were 70 degrees rear and 75 degrees front - not obviously wrong but certainly not typical (maybe except for Doug's Ukrainian project bikes?). My Rudge angles from 1952 measure (measuring the frame) 70 degrees rear and 73 degrees front, which I believe but still not measured with an accurate process and toolset. The Rudge's trail is about 40 mm, so I think its 73 degrees is reasonable. In the past I've done some such scaling from the pictures in Jan Heine's books, but in those the photographer specifically tried to minimize angle errors. My numbers were pretty close to what Jan claimed, but I don't think that proves anything.

To the Thread Starter: I'm envious at you having a Cyclery North bike! I'd love to find a 52 cm-sized version of that Hellenic design!

Kind of a final note: If my estimates of your frame's geometry are accurate, I think you have an odd bird there which might have iconoclastic handling. It would likely be different again if you convert it to 650b. Presumably the original builder had a sound idea of how the bike would handle and for whom, and that the bike would be an acceptable ride as he designed it either with 27" or 700x25 tires. I think I would build the bike today to follow the original geometry (adapting to my own fit) before thinking seriously about anything more radical, like a 650b conversion.