Fastgun locks stuck

So I'm loading the camper on the truck in preparation for leaving Tuesday, and 2 of my fastgun locks won't come off. One came right off, another I don't use because I'd have to unlock it every time I got fuel, but 2 are stuck. The key felt like it did not want to go in so I put a few drops of light oil in each and worked the key in and out several times. It now goes in somewhat easier but won't turn when inserted. I'm going to continue trying to get some lubricant in there and hope but anyone got any suggestions? It's looking like tomorrow I'll either try to find a locksmith or get a new cutting wheel for the Dremel...