They are not worth the money they would cost now. You need two pieces like Tx Jim stated. Even then you had better be on perfectly flat , hard ground or they would drop the loader real fast. Even on concrete they where not the safest thing to use. They would slide and get real fun. JD got to sell a lot of hoods and side screen from guys using the factory stands.
I had a JD 145 on a JD 2630 that I had to take on and off all the time. It was my only utility tractor at the time. So it got used to plant, spray, and mow/bale hay.
I finally just built a small 'A' frame out of heavy lumber. Then used a chain hoist to actually lift it. That made it much easier and safer mounting the loader.