Typical of my shake down rides, it broke three times. I kept tightening the collet, really reefed on it but the seat turned and the post pistons down from bumps. Too worn and the post is smaller with the gone nickel plating. I’m cleaning the grease out with a spray solvent and epoxying it in place. The next guy can use a torch to remove it. The chain is very noisy so I’m going to reverse it, it might be on backwards from original. It’s not unusual for old inch pitch chains to be noisy as they are old and worn and changing rings or cogs seems to make it so things don’t quite fit as they should. After about 6 miles the pedal with the nylon race froze up and the pedal kept coming off. This pedal had no grove cut for a lock ring, instead it had a spindle flat spot and a “D” washer that was missing. I made a“D” washer and that obviously let go at the 6 mile mark. Tiny “D” washers are not available. I’ll put on my new old stock pedals. So, epoxy, new pedals, chain reverse and crank arm tightening and I should be good. Even though the narrow bars were hard on the arms and shoulder and the riding position was pretty bad I did enjoy the ride. I’ll ride it more and keep improving weak spots until I’m happy. It’s actually pretty close.
It's already pretty amazing it's got this far. I would have expected even more issues to be honest.
Think it's time to put them NOS pedals on too and be done with - you tried but without more specialist tools some salvage jobs are just to difficult. For the seat-post I would hold back with the epoxy until you have tried degreasing and roughing the mating surfaces.
The riding position must be so weird compared to modern stuff. From your point of view all you must see is a front wheel in front of you - a road bike today would have the brake levers more-or-less vertically up from the front wheel axel, on this it's more like the rear edge of the front wheel! The bars have a significant drop too; would raising the stem and angling the bars forward help? (like this)