I've just been looking at the RickResource facebook page (I don't have a FB account). Saw this video of R.E.M. on the David Letterman show in 1984.
https://www.facebook.com/OldSchoolTimes ... 376904475/
Couldn't help noticing that Mike Mills has a non-RIC bridge/tailpiece on his 4001. Rather hard to say for sure exactly what it is, given the image quality of the video. It looks kinda similar to what you might find on a MusicMan Stingray - but not quite.
Here's a cleaner shot of it. I still don't recognize it:

Anybody got any ideas - or maybe know for sure?

