However a long ADM dovetail bar combined with one or two ADM dovetail brackets and one or two XY stage dovetail brackets, combined with a drill press and some bits, 1/4-20 or 3/8-16 taps will do the job.

Or any competent local machine shop.

Or order a long ADM dovetail bar and have it shipped to me. I will drill and tap the right holes in the right places and then mail it to you.