I am not familiar with the exact geometry of that elbow, but agree that it could probably
be fabbed for a bit less than 6 trillion. I have often dreamed of doing something similar
on my 300U/350U so that I could retain the underslung exhaust and clean hood, but get away
from the chronically breaking manifolds that were OEM.
I thought that the 330 and 300U/350U utility used basically the same sheet metal, correct? If so, I , and probably every other guy that works on these utilities has a half dozen 300U/350U
LH hood sections that has already been cut, and would gladly either trade, or sell you an already butchered, er rather, cut, hood very cheaply, at least for just under 4.5 trillion. I don't think
it would be correct, because the air cleaners were different (you will have to cut a second hole for your air cleaner pipe).
That way, if you change your mind, you won't have to source a hood section, and the restoration purists will
all be duly impressed with your strong moral fiber.
On the 300U/350U the manifolds seem to be a constantly failing part,
and folks that were using them, understandably, got fed up and just put a vertical exhaust manifold
(Which don't seem prone to breakage) on, so it is much more common to see a LH hood section that has been cut than not.
By the way, I run a Yale forklift that uses that C135 engine, and it has performed flawlessly for years.
The guy who sells me parts for my old forklifts always warns me- "Do not, under any circumstances, break the manifold on that Yale. If you do, you may as well throw the lift away". Good luck either way.