Removing rust from my 1990 toyota 4x4

I bought a beater with rust galore, especially bad are the doors and bed. I had a few theories:

First with the use of a router for my drill, cut out all the rusted areas, then get a fiberglass kit and layer it over the cut out areas. For example cut out a 1/4 of the bottom part of the door, then layer the fiber glass somehow from the edge of the door to the bottom part of the exposed door. Can this be done?

Second, cut out the rusted areas and rivet sheet metal in its place then spray with rust protection.

Third, just pretend the rust isn't there, just like the big squid...... exactly.

Any opinions would be appreciated, thanks in advance.

Same problem on my 1986 pickup... but remember before you go nuts with fiberglass, Yota replacement panels and parts can be found for like, dirt cheap. Just got to find the right place. Since you'll be doing either fiberglass or sheet metal anyway, apparently repainting is not an issue, so I'd just look for replacement panels new or used, rust free though. Shouldnt run you all that much, and in fact may cost less then the resin for your Fiberglass.