HELP 10 Speed rear derailluer difficult to shift
 

I have an old 1973 Ted Williams Free Sprit(Yes I know, its a bottom line but restoring and riding older ten speeds is my thing) that I restored last summer. Well the weather here in southern MO hit a high of 50 so I had to get out. Well I started to go up a hill and the shifting handle was very hard to push down. it went all the way down but the damn thing didn't shift. The chain just stays in the smallest cog. There is no tension screw either so that's not the problem. The derailleur barely moves but not enough to shift and I even adjusted the cable.

The first thing that I recommend is releasing the cable at the rear derailleur and removing the rear wheel. Then can you push the RD inward without too much effort? If it won't move pretty easily and then spring outwards again, then the RD is bad or maybe has something like a rock or stick stuck in it.

If it does move readily, then I'd start moving the shifter cable back and forth especially through cable housings. The cable could be frayed and sticking inside a housing. If that all seems good, see what it takes to move the shift lever with the cable loose.

I'm betting that new shift cables and housings fix the problem. After that I'd guess the RD is bad. The last thing I'd think would be the shifter.

That would be a 5 speed RD.
If you disconnect the cable from the RD, does it move freely within the housing? Does the shift lever move freely? Is the cable/housing original equipment from 1973? Does the RD move freely with no cable? Lever and RD may need clean/lube.