Reply to side-seat:
Probably not too difficult to build. I'll know better when I get into the adjusters on our D4's I have a set of those adjusters on the parts track frames we have to look at.
Good question regarding the prints, I didn't ask them their intention for any other parts, as I was specifically looking for the hydraulic adjuster for the D4 7U 4 roller.
Rome K/G: Not trying to hijack your post, but I did find another option for hydraulic adjusters from Paint Valley Equipment in Millersburg, Ohio they listed aftermarket hydraulic adjusters to convert from manual to hydraulic for the D4 and a few other early models (Allis HD, International TD) Part number PV310X which I found for sale on www.brokentractor.com as well as Ebay.
Eventually, I will get around to getting them installed, unlike the Henderson model, they don't seem to just bolt up...it looks like they are going to need some fabrication with the front idler arms...anyways, just wanted to share what I have found out there. We sure could use some of these companies to keep producing parts for our Cats.
https://paint-valley-equipment.dcatalog.com/r/PVE-Catalog/?page=28