I think that design isn't especially convenient to use. It has to be bolted to the floor, and unbolted if you want clear space. The four arms that support the cradle from the single central pole would get in the way considerably when working on the underside of the mower. You would also have to lay on your back to work on the underside, a practice which would get old rather quickly.
It seems to me that stand would be useful for a mower shop that essentially just works on the top of the mower, and probably lays it vertically on its side to service the blades. It would be left permanently set up, and rotated so that the repairer could stand in one place, close to the toolbox. I think I'd personally prefer a simple rectangular frame, on four legs that could be removed for storage. The rectangular frame could be the same as in the drawing - it would just need pieces of Rectangular Hollow Section welded vertically to the four corners, in place of the four support arms that go to the central pole. Four slightly smaller pieces of RHS would be slid into those corner pieces as legs. When finished for the day, you'd pull out the legs and lean the whole thing against a wall somewhere.
