Only kidding, can't recall to be honest, I was just going by the flange really.
Plenty of 'B' type 'boxes had flanged type outputs, as indeed does the one pictured.
There's no certain way of identifying it from a photo, except to say that it looks to be an FS5C71-B or FS5W71-B of the type that were fitted to many Nissan vehicles besides S30-series and S130-series Zs.
Short of opening it up and counting gear and counter-gear teeth, the simplest way of identifying it would be to trace it back to the car it was originally sourced from...