Thanks, I didn't know this one (and didn't look closer at the photo). However, it was probably less popular, than plain mle.1897, and is used also by other oobs, like USA. Besides, its color drawings aren't available
(BTW: if you'd accidentally plan some mid-life update of OOBs, than Italian 019 Obice Montagna should have a pic 301. Great work anyway! 
)
Michal