Gary;
what did you coat the float with? Looks like you did a Ohm test, so it registers.
When I last had mine out I coated it with a two part Epoxy and because my tank has the two expansion humps I centered the float as close to in-between because of tank design where it goes as to advoid the tank erosion that happens by the rubbing action. When you clean the screen in the fuel pump strainer, that black stuff is you float. Your first indication something is going on some where in the system.
I also took an old brass float from a Carburetor and mounted it, it should work but have not tried it yet.
That sender looks pretty beefy.
I used a material designed especially to re-coat insides of rusted fuel tanks after the rust has been removed - stuff seems extremely durable - the used float/sender Bob Weis sent me still seemed to be in excellent condition, float and all, so should have lots of life left in it - my truck still has the original setup, with no visible issues.