The M1918s ( shorter, and Standard Mle16 Chargeur) missed WW I, and were sent to Algeria and Morocco, where they were "blocked" to straight-pull only (By brazing a Block over the Gas Hole.)
If any are still to be found, it will be in Morocco, adorning a Berber Tent or a Mud-Brick House.

Some of the M1917s were rebuilt into M18s, and some M18s were built new.
As to the Original Long M17s, I don't know how many were made and survived WWI; they were definitely used by Frenchicon Infantry in 1918 (Photos exist). Field reports on usage are scarce.
I also don't know if the M17s were also "blocked" to straight-pull. Info on these in Morocco is not clear.

Doc AV