This is one of the most complicated classes of S.E.K. / O.S.E.
There is a lot of interesting info about them but will ''come'' as days pass
Anyway, they are built by Ringhoffer in two different places - factories.

BUREAU CENTRAL D' EXPORTATION RINGHOFFER - KOPRIVNICE /- NESSELSDORF /- STUDENKA / STAUDING /. ATELIERS KOPRIVNICE

BUREAU CENTRAL D' EXPORTATION RINGHOFFER - KOPRIVNICE /- NESSELSDORF /- STUDENKA / STAUDING /. ETABLISSEMENTS RINGHOFFER SMICHOV
Built in 1926 (papers also say that some of them were built in 1925 but i haven't find any one (yet)) , type Gglm-v.
Some photos for now ...

20 73 107 7 601-9 at Ipato
20 73 107 7 708-2 at a field near Amfiklia
20 73 107 7 713-2 at a restaurant near Doirani
20 73 107 7 733-0 at Lachanokipi
20 73 107 7 786-8 at Ipato ( the one at Tim's photo )
20 73 107 7 895-7 at Lianokladi
20 73 107 7 907-0 at Nea Magnisia, Thessaloniki