Nesdog,
Good decision on keeping, upgrading and USING the UO8. My '68 is a "Frankenbike" but still painted in the classic white livery with some repo decals. I ride it often and did well on it in a 1/2 Ironman last year with some "near antique" Scott aerobars.
SINGLE BEST UPGRADE, by far!, is the one for wheels. My LBS loves the bike. Hand built a set of lightweight 700c hell-for-strong wheels that are true and smooth. (Apprx $175.00 out the door for the pair) Used some 30-year old 105 hubs I had. Terrific difference in every aspect of riding, handling, and stopping. (A little "twitchy" compared to stock 27 x 1-3/8, but so what?) Squeezed a 7-speed in the back using the original rear derailuer (although some believe I am lucky to have it still in one piece, it has never given any trouble since new).
That's just my opinion. There are some really knowledgable guys here who know much more than I. I can just tell you about riding it, because I ride it a lot.
TysonB