Further problems

My problem is a problem with rust. The door jam where the door locks in place, on both sides the rust has rotted through thte meal leaving long holes. My question is whawt can I use to effectively fix this problem without cutting and welding

Is that the only place rusted?
Rust is hard to stop once started.

If lock plate mounting is rusted threw is is a cut out and weld in new plate mounting.
Ckeck your local body shop on the problem and get there idea on it.