Been thinking (again) about one of these. Spotted several 24"~ of 1/4" X1-1/4" strap I have salvaged from something else. Tried bending over a piece of pipe in the vice. That wasn't working well. Then thought about the 20 Ton press sitting there. HMMMMM? Yep, it'll make round bends!
Did some head scratching and started bending corners in the straps.
Used the band saw to cut things to length. I'll end up with about 16" in width and close to 20" tall if I want. This pic is from the side so you can see things better.