All the insurance talk aside, I suspect the plumber is at the very least trying to cover his butt, (imagine that?) A simple flange replacement might fix it or it might not. One option might be to replace the flange and not fix the ceiling under it for a while to make sure. Then again, as noted... 1962 is a long time for a shower floor to hold up....

I like the second opinion approach. Thanks for suggesting. It's worth $100 to me to try that.

It also doesn’t hurt to paint in a little 511 sealer now and again. Every ten years.

Second opinion said I have a lead pan and cast iron drain. He said he recommended just gut that all out if we want to re-tile anyway. It's time.