I just received my 2 Kato CSX SD70MACs and had a lot of trouble fitting the MT1015 couplers as recommended by MT. It was impossible to fit the MTs without trimming the openings on the body with an Xacto. Seems the opening is not exactly a rectangle. There are tiny little tabs in the corners that prevent the rectangular MT from fitting through the hole until you trim them out. Anyone else encounter this? I never had to trim to install MTs before.