HI Roger, according to the ZT parts book, the TSX-97 carb was used on chassis serial numbers beginning in '47 and through the end of '48. You are correct in seeing the last video having a steel/welded pipe between the carb and the air cleaner with a short section of hose clamped on both ends, top and bottom. If you wish to get technical, according to the ZT parts book, the hose for the '47 and '48 ZTs is a rubber hose and is the same as on the ZA series tractors. Hopefully the below link will work where you can see the hose itself. The air cleaner is changed beginning in the ZA series as well, but still on the right side of the engine.
As an FYI, when using the TRX-12 carb with an air cleaner on the right side, you use the same hose but cut the bottom elbow off as the carb has a flange that accepts a cast elbow flange where the bottom hose goes on.
I have seen many Rs and Zs with what may be considered an accordion style flexible hose because they are readily available at an auto parts store, not sure on price, but they are flexible. No harm no foul, as long as they work, do it to it.
Although that is "technical...according to the parts book," the tractors are yours and if you find a hose/pipe/ or combo that works for you, go for it. Yes there are some correct police out there, which for my particular unit ('40 ZTU), yes I am doing it that way. However, I, like many other people on here, are simply tickled to death to see new machines saved and put in the hands of a collector. Let's also remember, as referenced a couple different times in this thread, it was not uncommon to have an RE engine swapped in and out of machines. Likewise, I have been told by a handful of "old timers" MM did a good job of mixing parts when they were concluding one series and moving on to the next one as in superseding one another.
I hope this helps and the name of the game is have fun.
"Opinions are like eyeballs, [u:a84926bb5a]most[/u:a84926bb5a] people start with at least two."
Feel free to P.M. me if you would like and we can swap numbers and talk on the phone.
Aaron
http://www.agcopartsbooks.com/PartsBooksN/Viewer/book.aspx?book=agco/r1072d00