Don - great pics!!! Thanks for posting. Not a lot of guys have seen the inside of a lift arm where the rod is located.
Now, the question becomes what is the real problem. You seem to think the washer, which I thought was also the likely culprit along with the spring itself. The spring might look ok, but after 50 years its springing action has probably gotten weak. The only one I had apart before had a crunched up spring and rotted washer half gone so I had no choice but to replace with new at that time.
I'd have a good look at the bottom end of the rod and at the ratchet slots. They shouldn't be overly worn. I'd definitely get a new spring and new washer. At least since you know you can get the button off you can test and see how they work and if they resolve the problem.
I'm certain you ain't boring the guys on here. Your particular problem hasn't been discussed to this extent previously that I know of. And you provided a lot of great pics for future reference.