Hehe, yeah, this machine was all about the quarters. Yet it still somehow worked even when ported to home machines. I didn't know about Garrison, but yes, that definitely looks like a rip to me. I always thought Into the Eagle's Nest was similar, too, but I don't think it had the 4-player multiplayer. Obviously that was easier on some machines than others depending on their # of joystick ports. The ST one could apparently use "midi joysticks" in addition to regular joysticks.
Thanks for all the great comments!