> The shifter seems stiff, should the linkage be lubricated? With what? Where?<

I had the same problem on my '80 (since replaced with an '86). It was
somewhat of a hassle, but I removed the front half of the shaft that
connects the gear shift with the transmission. About 1/3 of the way back
it goes through a nylon bushing, and then connects to the rear half with
a clamp. I greased the shaft and bushing, put it back together, and
after some adjustment of the clamp, it worked beautifully.