I have a 73 Catalina coupe with a rusted out floor pan. I’m trying to find a replacement but not having much luck, are there any other cars that the floors are similar? Or maybe a link to where I can find a a replacement. Thanks 

https://www.opgi.com/catalina/1973/sheet-metal-body-panels/trunk-panels/

and much more for your car.

Don't know if you plan on doing the work yourself or having it done. If you are familiar with sheet metal ignore the rest of the reply. I have a Lincoln DC 250 power source with a LN7 wire feeder on it, right next to the tig welder. When I started the sheet metal work on mine I purchased an inexpensive mig from Harbor freight that will run an .025 wire. It works great on sheet metal as well as other things. Since I bought it I almost never use the Lincoln. It works a lot better than I ever expected it to. For whatever it might be worth.