Here is what I did for my mount:
taped 1/4-20 holes on the tackform base, the holes were already the right size.
3Dprinted a support and bolted that to the aftermarket tray I had on my jeep. I used #8-32 machine screws with washers.
Using 4x 1/4-20 bolts secured the base to the support I printed. So far so good! If you would like the CAD file for the support let me know.
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