One of the best parts of this hobby is there are unknowns that are unknowable. The hunt is more fun than the kill.This is one of my favorites...allways figured there was some mystery to it.
I've been doing this for 20 years and spent hundreds of thousands of dollars on water cooled guns, parts and many many books in search of answers. I've spent weeks deconstructing old parts and making new ones for these old guns so they can keep running. To suggest I'm in this for a "gotcha" moment would be insulting if it wasn't so hilarious. You'll have that dealing with text. Things get lost in a perceived inflection and assumptions. I have no doubt this discussion would have a completely different tone in person.
We can argue about what a "mis-identified " picture is or isn't. It may be insignificant, but it seems no one knows for sure whether or not a simple stamp on a sideplate of "1928" was an Argentine specific thing in 1929.