MatthewRyan, strongly suggest you heed advice from people with more knowledge/experience in the matter; if you plan on just doing whatever you want anyway, then stop wasting everyone's time.
The pistol does not shoot over 370, so you won't be able to import it.
The receiver won't pass by itself.
The receiver won't pass as a replacement for the pistol because the pistol isn't admissible in the first place.
Ultimately you can always talk to Evike (strongly suggest against doing business with them) or whatever other shop, to get something like that lower and have them pre-strip all the parts off the receiver and send those alone.