Looks like an older style Gamo trigger unit to me. But many of the old Crosman springers, like the Quest, used a copy of the Gamo trigger so it could be a Crosman unit. And given that many of the parts used in the Quackenbush guns were from Crosman I'd guess that it's the Crosman version.
i would just repair the worn part. If its just worn down so it would catch you could weld a little on the worn spot then reshape it with a file. Nothing to loose trying. Theoben also used a trigger that looks similar to that one in the rapids.
By the way, there should be an engagement adjustment screw in the back of the housing, behind the trigger blade. Turning it CCW might get your gun back in the game while you're waiting for the replacement parts.