Rob
Yes - and this helps if the lids have been swapped!
Colin

Just found the markings under a lot of crud, it is marked 2 SYN 3219 A, I guess that makes it a 3 synchro box, don't know what the cut out on the casing is though, under the plate I assume it is the selector plate sits in 2 half rounds in the casting, next to this is a half round about the size of a 1 penny

Ron

Location: Kent

The extra half round cut out is to allow the removal and refitting of the mainshaft. That makes it a 2/3/4 synchro box.

Location: Gard, France 30960. Used to be Languedoc-Roussillon but now it's Occitanie