Help. I'm writing from the edge of blindness after working for an hour with the MTL #2004 coupler, getting it ready to install on the tender ofmy Spectrum 2-8-0. First, I assume that I will have to remove the old coupler pocket, file the tender bottom smooth, and drill a hole for the new pocket. Is this correct? I can't see any way of fitting the coupler in the original pocket. But I'm waiting for reassurance before I cut the old pocket base off.