I'll keep the spout, but the hot/cold cartridges are OLD and can't find any replacements. I went to 4 plumbing supply houses in my area and they said to start over. I just need to replace the hot and cold and keep the plumbing basically like it is. 1/2" hose with sharkbite connections per pics. What can I buy to make this functional?

just get a new rough+trim kit if you can access everything
you've already wasted hours looking for random ass cartridges
those are poly crimp lines, you can probably just unscrew them and screw into new rough kit

>>2923596
this desu just replace it all, it should match up

>>2923589 (OP)
you should try a trailer/mobile home place for replacement parts.