I will chime in with my thoughts/comments with the H/W Carb. It has been a while since I posted so bear with me.
I agree that the linkage is unnecessarily complicated and the lack of instructions was frustrating. Using the fuzzy picture to put the puzzle together was not what I expected when I ordered the set. FWIW, I installed this carb/linkage (I still use the linkage despite its shortcomings because it works) almost 5 years ago. Sounds like it has not changed at all.
The carb works great and I concur with you on the choke. I installed a manual choke kit on the carb and it works fine. I wanted to keep things somewhat original looking on the inside despite the change. I also did not want to run any more additional wiring or the dreaded heated water hoses to make a hot water choke function. BLUF, a manual choke works fine with this carb.
I am not sure what to say about the adapter plate or the air cleaner stud. I did not have those problems. The adapter that is sent is commonly available at your FLAPS though and you may want to check with a local place to see if you can find one with more well finished ends. To maybe allay some of your fears, I do not experience any leaks at the manifold junction that you sounded concerned about.
Overall, despite the shortcomings, it is a great carb and a great setup. I did not think the shortcomings in the linkage kit were any worse than some other kits I had received (brake cyl kit) from other sources and the tech assistance that Tom provided made up for any shortfalls in spades.
No flames here, just my 2+ cents thrown in.
