PhilaGardener, It doesn't take much in the way of tools. You do need a small welder, and some way to cut metal, people cut steel with a cutting wheel on a saw a die grinder. If you want to build this or something like it, that would be an excuse to buy a couple inexpensive tools. You can grind, drill and cut a metal into any shape you want. If you'd like to make one of these, or anything else, I say do it, It's easy.
If you decide to build one I'll help.
The shaft on the engine is 1 1/8", an 1 1/8" centrifugal clutch cost 3 or $400. I plan to start the engine, then file/sand the shaft down 1/16", that will leave a 1" shaft, a Hilliard centrifugal clutch is under $100, a mill should be fine with that.
This side is a little trickier, because I'd like them to slide in and out without too much slop. When the two outer tubes are tacked they pull and distort so I welded clips to the metal plate to hold them in place. when they pillow blocks are bolted on with the shaft they at first wouldn't slide, and required grinding.
Another spreader needs welded between the forks, but the band blade snapped before finishing the cut, blades have been ordered and should be here Wednesday.