It'd sure be nice to have a "stock" dolly that would hold most implements, but ....... alas, all my implements have different footprints, weights and so on. So, when I finally built a garage with a level floor, I made a dolly for each (brush cutter, box blade, rake,
chipper/shredder), except my FEL, which I just drop onto the garage floor. I used 2"X6" planks, screwed together, and 4 large dolly wheels per implement(tried using smaller ones, with 6 wheels instead of 4, but they are harder to push when loaded). Mounted each implement on the 3pt, brought it into the new garage, lowered the implement until it was about 9" above the cement floor, and then configured the planks underneath the implement, plus any special supports needed (e.g.,
chipper/shredder will tip forward if there isn't a post under the 3pt attachment), and just cut the wood accordingly. Nice evening in the garage, a few beers, lots of music in the background, and now all implements have a "home". Sure beats my prior 4 years of just dropping stuff on the ground, and dreading the crowbar/hammer/swearing that was sometimes needed to remount an implement.