Patience my dear fellow.
We'll need to know what year BMW the donor tranny is coming from... very important
NOW, this is your tanny -
http://www.realoem.com/bmw/showparts...16&hg=23&fg=05
THis is a 91
http://www.realoem.com/bmw/showparts...16&hg=23&fg=05
They all look the same and they all carry the same serial number. AND... upon closer inspection of the page you'll notice the wording "UP To 12/92"
So, upon inspection of these results from
http://www.realoem.com I would state that any transmission that comes from an earlier vehicle than yours must be from an e36 build date 10/90 up to 12/92.
Hope this helps and good luck with the tranny, sorry to hear that it broke.
surge