Hi Tony,
That top contraption is not a Losmandy part, remove it by loosening the large silver knob under the wacko bolt and knob. If the resulting saddle is 3" wide then you should buy a used or new saddle for your GM8 that has the Losmandy "D" and the smaller Vixen style saddle clamps. The current GM8 saddle is designed to accept both Losmandy and Vixen dovetails correctly, it looks like this:??

?
This part is only $55 plus shipping so not too bad and is the right way to solve the problem.?
Cheers/Chip