1976 4hp Chrysler outboard 42HB Fuel tank problem

Hello, I was wondering if a external fuel tank with a hand pump would work on my 4hp engine. It does not have a fuel pump what so ever and it relies on an onboard engine mounted gravity fed fuel tank to a carburetor. I inherited this from my great-grandfather and it had 20 yr old gas in the tank and it was rusted up and down on the inside, the carb was all funked up with old dried gas. The fuel tank is the only thing I cant keep clean, (rust... go figure) tiny tiny particles keeps on fouling the fuel needle even with a inline fuel filter. Any help or suggestions are welcome, thanks in advance.

It would take some work to save the rusty tank. There are kits made for this sort of thing. Results will vary I'm sure.
Here's a link that may interest you..............

http://www.kbs-coatings.com/cycle-tank-sealer-kit.html

Was at a NAPA parts store the other day.
They had on the counter a bottle or can of a sealer.
You add it to the tank and swish it around and then let it dry(follow their instructions)and it encapsulates all the uglies in the tank.
It's gas proof and allows you to reuse a rusted, leaky tank.
Install a filter between the tank and carb.