fuel sender gauge gasket

All great info, so glad I posted. I'll re-use the old retainer.

I'd also like to buy the tool to make it easier. Are they readily available at any auto parts store?
What I'm saying is the original retainer may be gone and replaced by the aftermarket retainer so reusing the existing retainer may reproduce the same leaking condition. No need for the special tool. hammer and BRASS chisel is just fine.