A question only you can answer. That depends on the extent of the rust and your level of experience/ability. A complete novice with limited time to work on their project might be better off buying a patch panel for their specific car. Obviously would be cheaper to make your own. Buy a sheet of metal and watch a bunch of Youtube metal working videos. Make a pattern of your patch before committing it to metal. I use 12 pack pop/beer boxes sometimes to make my patch patterns. You really need a welder and a flux core unit won't work worth a crap on sheetmetal.