Rust particles in Carb & Tank

[RodC]

Well I just rebulit my carb, (Quadrajet) There was a thin layer of rust particles in it. I have seen worse. The former owner had never filled the tank past half full because the gas cap leaked, (gee that's a hard fix) so I bet the top half of the tank is rusted. any whoo, my questions:


The filter that was in the carb was one of those plastic screen types, if there was a paper one in there would it have stopped more?

Should I Put a bigger filter some where else, if so where is a good location?

Should I replace the tank, or would a good filter and changing it a lot work.

I'm hope'n that someone else has been here before.