Craig, I'm using a Glide Engineering seat in my 46. You might be able to mount your seat similar to what I did.

I bolted a piece of 3/4" plywood on top of the seat riser and mounted the seat to that. My seat is not adjustable but you should be able to get some adjustable mounting brackets from the junk yard that should work.

If you want, email me directly and I can send you a few pictures of what I did for my 46.

Hope this helps
George