I can take measurements today or tomorrow (they are in my garage) with a picture and send it to you. Please click on my username and "send me an email" with your email (my PM box sometimes fills up so email is easier.)
I know to a certain degree that the saddle supports are SOMEWHAT universal. I found that a set of Honda 750 Magna supports fit my Raider. They were smaller by I'd say about 1 or 2mm ... all I had to do was stretch the opening by hand that extra 1mm and they fit perfectly. Unfortunately they too were too 'tall' the eyelets to allow me to use my OEM Yamaha back rest. I ended up shelling out the $110 for the Yamaha supports.