yes Yugoslavia (although the information is not very clear) and have been used both by R.E.I. that E.N.R.
Different data on the pre-armistice availability/distribution of the ZBs are present in the publication LE ARMI DELLA FANTERIA ITALIANA 1919-19145 by F. Cappellano and N. Pignato (I’ll try to find if maybe there is a PDF)
some photos
bonus photo
MG15
