I made my own. If you look at the picture it is a flat plate (quarter inch thick on mine) welded to a thick wall inch and a quarter steam pipe four foot long. On the flat plate you have to bore five holes. Four small 5/16 inch bolt holes that match the U-bolt (I used four bolts welded to the plate that stick through the pinion yoke's U-bolt holes instead), and a big hole in the center to clear your socket that is tightening the pinion nut.
If I had thought ahead I would have fabricated some bracketry (two flat plates with a three inch arch cut to rest against the top of the axle tube and spaced far enough away to allow you to slide the handle through two holes frilled in the plate to fit the handle through) that would allow me to just hang the tool over the axle tube and let the tube hold it in place while I torqued the pinion nut to crush the sleeve. But since I needed to hold down the housing as well, I tied the whole rear end and tool to a set of eye rings I welded on to the back bumper of my one ton tow truck for pulling my race car on it's trailer. (a welder is a very handy tool to have).
To slit the steam pipe to fit in the steel pipe I used my friction saw to carve a slot in the end of the pipe to hold the plate. (a drill press is another very handy tool to have, especially when drilling really big holes in thick steel plate).
If you check your yellow pages I'm sure your town has a welding shop that can fabricate something like this for a tenth to a fifth of the price of the tool.