I still have a little 12v compressor. It came with a fifth-wheel travel trailer my folks bought, and used up. Forester brand. We salvaged it before carting it to the dump, and that was my little prize. It was hard-wired, so I had to buy a cig lighter plug. Not all of those little compressors were cheezy, this one builds (slowly, it's TINY) up to 140 PSI. Originally used to pressurize the fresh water system.
Maybe check with a RV supplier?