Do it....even a single speed one (like on my 102N-VM below) ....and then come back and tell us how "easy" it was
Might not be too difficult to make a half ass one,
I've used a "half assed" TS mod on production shift work. Simplest of mods, and it paid-off for the company many times over. "Hand lever" conversion from screw-operated. Cheap, cheerful, and very useful. Easy enough to justify the modest effort to implement, and "reversible" back to screw-operated if need be.
Going the next few miles to starwheel/capstan, two or more ratios, dogs or clutches to select options and/or provide for power is harder to justify.
Unless a given shop actually HAS an otherwise hard to satisfy need, and "lots of it", it may come out as a lovely to behold, but seldom actually NEEDED "decorator".
The most prominent "feature" of Cazeneuve's complex one? The massive Mike Foxtrot tears 3 inches out of the already scant 30" c-to-c daylight budget, and is a bit of a chore to even position!
That said, with a # 5 MT hollow ram, it could not do with adequate stiffness some of the things it was meant to be able to do if it was any shorter on the ways, nor any less massive.
There are reaction forces involved when a TS is to be asked to do serious work.
As to DIY
from scratch?
It is less money, time, and hard work to
adapt a store-bought ready-made turret - even if of some other tribe and race than that of the lathe it is mated-up to.
A proper turret may not be as "elegant" - many are a tad on the ugly side. Most just get in your way when not needed.
WHEN tasking justifies their use, they are more universally useful
for the time and money invested.
No law a person cannot own more than one TS, after all. Once "fitted", they don't take that long to swap, "vet", and put to work.
If I'm to "DIY"
anything for that, it would be a crane or "skyhook" to make the swap easier and safer. Even then I do not wish to start "from scratch", only modify stock goods.
Lazy, Iyam.