Whether this tests the plans for purchase program or is an offer from Frank S, I like it.
Details that Jon and DIY'er listed are there and stress analysis even! Full size drawings and a 30 day return of funds, etc are the deal of the century for 10 bucks.
Way back, stands I purchased [still have em...under the El Camino] needed one additional feature. I drilled through the stand, 90 degrees from original hole but lower; by half the hole spacing on the tube. This increased the increments of adjustment X 2 without weakening the structure at all. The added benefit; could rotate the 3 feet so the 'apex' was outboard, allowing that extra couple inches between for the creeper. Only needed to extend chain attaching the pin.