new gasket, new seat, faucet still leaks!
 

I have an ancient sink [1945 edition] that I just installed and I just cannot get the cold water faucet to stop leaking. I have replaced the gasket seal twice, and the seat once. I also removed the sink and put teflon tape around it. Still no leak stop.

It is not a big leak, just a fairly steady drip.

any thoughts?

Oh, yes, the faucet is the standard type with a screw in body and gasket at the bottom.

Welcome Muskox:
The 1945 sink is surely made of cast iron and over tightening the faucet could have cracked the body. The new faucets are not made as strong as they were back then because the new Stainless steel sinks will flex a bit to make the faucet seat well.
Use a magnifiying glass to look for cracks in the faucet body. The next time you set the faucet try a worm of plumber's putty around the it to help it seat in well.
Glenn

Sounds like you might have to grind the seat before installing the new seal/gasket.
If they still make them, I would expect you could get the tool from your local big box or might have to go to a plumbing supply store.