As part of compiling my sources from American Machinist, I found this photo on page 876 of Volume 49 (November 14, 1918 publishing date- found from this source):
I have no idea what this howitzer is, or if it is even a real photo/illustration (it might be just an error and it's a 6-inch Model 1908). It seems identical to a Model 1908 except for the bigger/thicker trail and the extra cylinder above the recuperator.
-- Edited by AN5843 on Tuesday 7th of April 2020 02:43:29 PM