UCWRG is a great outfit! I communicate with them pretty regularly. They are perfectionists over there and everything they make and source has to be perfect. I do not know where they source the lower parts for their LPKs, but I have no doubt they got them from who they believe to be amongst the best supplier(s). They do not source junk. The items they make in house are also held to a VERY high standard. Their grips are awesome, so don't be so quick to want to part ways with it.
Disclaimer - Yes, I am one of their Distributors (non-FFL).