Well Paul, you posted on Tuesday morning and it is now Friday evening. I am sorry to see that response has not been exactly overwhelming. If you want to go to page four by clicking on them little numbers down at the bottom of the page, then scroll down to the fourth discussion thread on that page, titled "Your Challenge - should you choose to accept it" and peruse it, you will see some pictures of some of the work that I did fabricating something to convert a slot hitch on my WheelHorse to work like a sleeve hitch, powered by an electric linear actuator.
I know that you wanted to make a sleeve hitch and this is not the same thing, but it might help in some way. All my work was done with a metal chop saw, cutting torch, drill press and a welder. Those square holes are nice, but not necessary perhaps, you can use a hex head bolt and lock washer in most applications instead. It is pretty tough drilling large holes in thick metal, but it can be done.
You can weld two pieces of metal to make correct angle that you want, or use a big vice, cutting torch to heat the metal cherry red and a cheater on a big pipe wrench and a heavy hammer to bend it to the angle that you want it.
Doing stuff like this is a challenge in a home workshop without the advantages of hydraulic brake and presses etc, and takes a little innovation and ingenuity, but can usually be done in a satisfactory manner. Making things for light equipment like garden tractors, you do not have to be so safety conscious about meeting welding standards that would stand up to high way speeds where a failure could be life threatening. Most stuff you make will probably be more than adequate for use on garden tractors. Sometimes you have to go back to the drawing board and do a little modification or try someting a little different.
I also made some sleeve hitch adapters to make it easy to put trailer hitches etc. on them conviently and quickly, and sold a few on ebay, but it is pretty labor intensive and I am not set up to do that kind of thing really.
Good luck with your project, if you are like me you will find it fun, absorbing and rewarding when you are done with it. Let us know how it is going.
Best regards.
Bill P.

who needs quantity when you can get quality. Bill, thanks for the info. The bit about the cutting torch is exactly what I needed.

Your Wheelhorse projects are what inspired me to post in the first place. Thanks for the information.

-p

Glad if I was able to be of some help to you Paul. Let me know if there is anything else that I can do. Be sure and post some pictures of what you come up with.
Bill P.