I inherited a platform frame but it turns out the welded on pins are CAT 2. 7/8 inch plus rust. It mounts fine on my old MF 135 since the lower hitch balls are well wallowed out to the point of falling out of the sockets. I need to learn to weld or drill holes for new bolt on pins.
Built this one years ago out of scrap. A frame for snowplow, some sweet steel from the dump, a receiver hitch I kept from a traded vehicle, 3/4 marine plywood from a dock. Had to buy hinges and hasps though. Built it for my first Kubota, three tractors ago. Didn't use it since I got my RTV so I loaned it to a friend, now it's on his second Kubota !