ke70km/h

I was just wondering how you guys handled rust in your corollas lol since we're all driving vintage machines. The boot in my ke70 is almost rusted through and spots around my petrol cap too. I'm thinking of taking up oxy acetylene welding. Maybe cut out the rust find a piece from a donor car and welding back into the hole. I don't want a crappy bog job lol because my ke70 deserves the best.