I make a lot of jigs and most of the time I just glue them up,that's one of the neat things about MDF it holds with just glue..
Problem solved Bob.
I just ran across a piece of 7/8 thick live edge maple I had bought on the cheap to use for box lids. I cut it a few weeks ago and got 2 lids and the remaining piece is only 1/8 inch shorter than the plan calls for and I doubt that will create a major problem as well as the extra bit of thickness considering it will be the fence. The rest of the jig can be made with the MDF because the fasteners go into the face and all the way through for adjustment slots and hold downs.
Thanks again for all your input.
When something is advertised as being foolproof there is always a better class of fool that comes along to prove them wrong.