Turns out that I gave y'all some bad info. The trans from my '84 300 SD is, in fact, a 4 speed Mercedes unit. I had a chance to talk with Jeff the trans guru (not one of his underlings) and mine IS a M-B unit. Evidently a number of the earlier ones were B-W but not by the time 1984 rolled around (I don't have the dates for the B-W era). Jeff said the B-Ws were 3 speeds so if you have an older 'Benz with a 3 speed auto it's probably a B-W.

I'm guessing that the English-seeming bolts I ran into were probably the result of deterioration on metrics and not actually English after all.

Trying to keep the info accurate on here -
Dan