If you’re in the Eugene/Springfield/Junction City area go check out Armac Tactical. Good people & cool little shop with some great stuff. They are in downtown Junction City, just off the main road.
They do lower engravings, gas block dimpling/pinning, and I think they are the second largest Aero dealer in Oregon!
I don’t work for them, I’ve just done business with them, and my FFL buddy and I are big fans of them!