Well! Thanks to Cal (and tons of input and support, brains knocking together, etc....) as the part arrived tonight!
The nut size is correct and also, the little brass washer she found in the bottom of the tub one morning looks the same! Fingers crossed!
Heading up Friday after work..... Have to shave some of the wall to get my 1" deep well socket on it but I got everything ready. Nothing a little Roto-Zip can't handle. 8)
Since it's so old, I'm thinking I'll put a little wire brush on my Dremel and clean up the joint before I try to untorque it.
Got the torch.....just in case. 8O
I gotta tell ya....every time I go there...it's all about work and I'm usually filthy by the end of the day. It's going to be nice to take a real shower....