Any idea which Getrag 5-speed this is?

Being a BMW freak as well as a 1200 freak, I have a couple of Getrag 260 5 speeds in the shed from e30 2.5L engines... the boxes are fairly compact, and have a remote shifter, so you could almost make the linkage as long or as short as you like so move the position of the shifter around. They also have a very sweet shift, much better than the old 56 in the 1200 ... and Z3 / Z4 short shifters are a direct fit also!

If someone was to make up adapter plates for these, they would be an excellent box behind the a-series, and they are readily available from the wreckers these days.