Well chain would make it Borg Warner, if it doesn't have a selectable diff-lock that makes it Borg Warner.
If it does have a manual diff lock that makes it LT230
Anyhoo, all the B-W transfer boxs are the same, manual, auto, 3 speed, LT77, R380 et al.
With the possible exeption that the handbrake backplate mountings were put on pretty much at the whim of some guy in a small hut in Bavaria. I was chatting to Simon from X-Eng on Sunday about the problems he had trying to get a standardised backplate for the X-Brake to fit the B-W, so my advice is fit one complete with handbrake.
AFAIK you can put it pretty much straight on and the B_W doesn't have the issue with wearing the gearbox output shaft either.
I therefore sugggest that you fit the T-box only from the scrapper, the 3 speed might be "agricultural" by RR standard but it's the strongest auto box they fitted.