Got some hand forged iron butterfly hinges from Amos at Peque Hinges in Ronks, PA. Will install on cabinet doors. It looks like the back flap screw holes 5ED055DD-5BFB-41C4-879B-31F44B7D9554.jpg73619FDB-6F37-4034-86E7-3A9E1D84DE22.jpg73619FDB-6F37-4034-86E7-3A9E1D84DE22.jpg0C061D2D-5206-46FB-BA13-7F5BB9DBA6E7.jpg re countersunk and I think I will mortise the back flap. The front butterfly wing will be surface mounted. The screw holes are not countersunk & I think that is OK. Any advise on a method of work for installation?