I also have 4 AHM c-liners. When I got them they were very common. They are only powered on one truck, but it is self contained. I got a bunch and double powered all of mine, it is a drop in job. They are still running after 25 or so years. I have two converted to DCC now and 2 on the shelf. As mentioned, the mechanisms are lightweight, but seem very well engineered to me. I filled ithe big holes in the pilots, shaved off the cast grabs and added wire ones, and put on PRR antennas. I also repainted PRR freight scheme. I did kitbash a B unit out of 2 As.
Do you have any pictures? I'd love to see those.