Since my E28 is an conversion from auto to manual, I’m crawling under it today to figure out what transmission it has. I’ll throw it out here with the best picture I could get before raising it.

What say you, oppo hive mind?

UPDATE

Enhance!

The VIN in clear, and shows an 1987 535 with a manual transmission. Couldn’t get a good picture of the stamping, but it is 260 0 1302 91. So it is a Getrag 260.

One mystery solved.  Many more awaiting.