Fitment issues - Elftmann Tactical Elftmann ELF-SE Trigger

From Elftmann FAQ website: "If your rifle has a standard mil-spec AR-15 fire control pocket, our trigger will fit with few exceptions. The exceptions include manufacturers that have a larger radius at the front of the pocket – our triggers fit, but some material must be removed from the receiver."
I installed in an Aero AR15 lower and had to grind the front pocket so the pin holes line up. After doing this, installation was straight forward.