I have a pair of 100mm (4") ADM guide rings in excellent condition. The dovetail adapter is for Vixen type rails. I've used this with my RC8 and a Tak FC-60. Also you have a choice of either 1.5" or 2" delrin tipped screws (shown). I now use an OAG (for better or worse!) so these are no longer needed.
Asking $70 shipped CONUS. (New price is $99 + shipping!)
Paypal only, no fee.
Any questions, please ask.
Thanks for looking,