
Bang on John , and Gecko Andrews has these for $29 , just bolt one to the top of your mount and slip the 'Vixen' style dove tail thats bolted onto your tube into the $29 'FF561' , just google 'Andrews Communications' click on 'telescopes' ( bottom left) , click 'Gaun Sheng' and almost at the bottom of that page you will find part# FF561 thats what you need .
Also with one of these on the top of the mount you will be able to fit most scopes to it , the Vixen dovetails are very common .
Brian.