I think the angle drive needed is a Smith part, the gauge manufacturer. The model numbers are something like BG2410 or BG2401 with a suffix denoting the plate that helps mount the angle drive to the specific tach (not really needed I think, or you can mod the plate or make your own...)
I decided not to waste time on the angle drive, and used info from another Europa owner who said he swapped the speedo and tach, then the cable runs to the speedo easily with no tight bends.
It was easy to do, just remove the two clamps on each gauge (from under the dash, no tools needed, just thumbscrews) and you can pull the gauge out of the front of the dash to get to the wires and cables without crawling underneath. If you want the trip odometer reset cable, you can remount it on the left of the dash or just leave it hanging under there.
Hope that helps!