MadReferee's design is similar, but not exactly the same. On MadReferee's, the reinforcement piece joins the main vertical frame at about a 45 degree angle. The Leinbach reinforcement piece goes higher up and joins the main vertical frame at closer to a 30 degree angle. MadReferee's doesn't seem to have the horizontal member extending past the the place it intertsects with the reinforcement bar. The Leinbach has the horizontal member extending past that intersection about 4 inches, enough to catch the rear tire bars at full lift (on a subCUT). When I trimmed the excess off, that was no longer a problem.
I got mine from a local guy who only deals with aftermarket attachments. It was marked $125, but he gave it to me for $100 because I bought about 7 attachments from him at 1 time. That was 4.5 years ago though. I could not find this exact model on Leinbach's site, yet did on the Adams site. You might want to check the Leinbach site for a dealer closer than Adams so the shipping doesn't kill you. You might also want to call Leinbach to see if they still make that model. If not, buying the plans from MadReferee at a discount then buying the materials locally and taking them to a local machining & welding shop could be a way to get what you want.
Good Luck