I thought about trying keg lube, I guess that would tell me if it was leaking through the threads of the plastic body. I cleaned it so the problem isn't foriegn matter. Not sure what a gasket would do unless the problem is the threads not sealing. I'll see what I can do about that, I just assumed the spring was getting weak and the pressure was pushing it up.
I already scoped prices on ebay but since it isn't mine I'm just going to pass the info on. Might buy one or two for myself, just for backups. I have everything but this item in my repair parts stash, go figure
I know the guy who gave him the keg so I asked him if he'd ever used it. He hadn't so he didn't know it wasn't holding pressure. Its a nice looking keg too.