Tuning Leaking Mutant Shorty

Looking for a little advice here. I have a Tiapan Mutant Shorty that I just love. It's lights out accurate, super quiet, and just fun to shoot. It reciently started leaking and I just got around to taking it apart, hoping replacing a few O rings would fix it... it didn't. I'm 90% sure its the regulator. I could order a Huma reg or try to repair the one I have, but I'm busy these days and am thinking about just sending it out. One issue is just getting the right O rings. I can't find anyone that sells a kit for the Mutants, unlike FX and other brands. Can anyone recommend a repair service for Mutants, or tell me where I might find an O ring kit for the gun.

Thanks!