[kens_74_911s]

Been there... I agree to do as mentioned remove the screen and clean it. Flush some gas through the tank (you can leave it in the car) and you will likely see the particles exit. you can probably go a few months just doing that at least until you have an opportunity to pull the tank and seal it.
I need to seal mine... When I get >1/2 full the seam seem seems to have a few pin hole leaks. I have an early tank in my 74 so I can run a normal size spare and have capacity to hold the flat up front if necessary.
I was just looking at these videos just yesterday:
Videos - Demonstrating How To Use KBS Coatings - Stop Rust
It may give you an Idea of what the process is. The KBS product recommended not using the tank for a week? I think other brands kick off faster.