I just bought one a few weeks ago that hasn't been run in 10 yrs. I haven't had time to get it running yet so I can't say I've had a problem with it.
Mine came with the 3 point setup and the manual I got with it shows the IH hitch setup. I've been going back and forth on IH v 3 point and decided to go 3 point since it already has the brackets. Basically the 3 pt arms connect to the 5/8" bar on the front and 3 plates bolt together and attach from down low on the tiller to the top link mount on the tractor. I think those brackets set maximum depth and keep the tiller from nose diving because the plates will scissor together when you lift the tiller up (guessing because I haven't hitched it up yet). It doesn't pick the whole unit out of ground rather it picks the tines up and rides on the back wheel. I'm pretty sure you could substitute with a length of chain for those plates. I saw the IH hitch adapter for sale here
http://ihccw.com/sleevehitch.html, but its way out of my price range. If you already have an IH hitch on your tractor, I think the tiller manual has enough pics to build one. They are available for a few bucks on everyone's favorite auction website. If you want some 3 point bracket measurements or pics let me know. Here is mine and the IH hitch from the manual.
Bill