i made those clamps.

Right then, i measured the tube i wanted to clamp (the 1 1/2" tube measured 38,2mm), and used AutoCAD to draw the clamp.

i then e-mailed my drawing to a laser-cutting company, and asked for 6 of them from 10mm steel plate. they charged me about £100 (uk).

then i cleaned them up with a file, drilled some holes, cut them in half and tapped the threads.

does that help?

 Did you make those or buy them?