Pat, sorry for the delay. I got 8 stitches in my right pointer finger so I wasn’t doing any train work for the last week. But I was able to measure the motor mount.
•large dia. flange (motor face side): 1.255” dia X .138” high
•next step: .825” dia X .257” high
•last step (inserted furthest into truck): .610” dia X .277” high
•square boss protruding from the side: .200” wide X .257” high. Protrudes .076” past the large dia flange.
Take a look and let me know what you find. I appreciate the help!