Great job and photos, watergoblin.
Years ago, I had Marv at SOR round up some of the parts, including a linkage rod from an xfer case that was way too long (oops). I made the rest of the parts out of galvanized pipe nipples, and brazed a metric-threaded shaft into the home-made lever to accept the OEM shift knob. This is a great 'fab it yourself while standing in the plumbing aisle' type project. All I used was an electric drill to drill out the piping 'tee' that served as the lever mount and pivot point. It took some fiddling and adjusting, but it works like a champ.
I agree that there's a total lack of any factory or reman linkage parts for PTO winches - this was true 23 years ago when I did mine.