Hi Humble Pie,
I've had similar issue in switching from crinkle hub to full-width. (Don't ask why - it seemed like a good idea at the time). No-one could give me dimensions so I made my own drawing. I've attached a JPEG but if anyone is interested in getting the .DWG "Autocad" version (you can then extract all the dimensions), let me know and I'll email it. BTW I used Draftsight beta a free CAD package from Dassault. I could adapt the drawing to the earlier version of the swing arm if you are interested. No guarantee that my school ruler has accurately extracted the dimensions of course but it seems that BSA concerned about repeatability, either...
Regards
Gary