Bit late to the party on this topic as I've been away for a few days, but I can add that in Romanian manuals this particular projectile is known as "Trotyl mine shell".
Same manual describes it as being 292mm in lenght (291.8mm working from the plans) without fuze and coloured blue-grey with ochre-yellow ogive. Occasionally some would be unpainted with yellow painted markings.
Fuze would have been 3ГТ ("3GT", where the "G" stands for "голова", "head" and the "T" for "TNT/Trotyl"), 13ГM (the "M" stands for "Melinite" - also, I couldn't find an exact drawing of it, but here's one for the extremely similar 17GM - I believe the only difference is in the booster) and the model 1884 percussion fuze with separate booster.
Here's a provisional drawing of it from the book on Romanian ordnance I'm working on - provisional because the finished piece will have the exterior of the shell much more rendered, with shadows, reflections, etc).
In WW2 this particular shell was known as "Nr.5" (it would also have been repainted yellow with Romanian style markings) with a version fuzed with a Romanian U1 fuze known as "Nr.5M", while the Romanian ordnance codes for the guns that could use it were 22 and 22a respectively - these were the "Tunul de câmp Schneider-Putilov Md.1902" ("Field gun Schneider-Putilov, Model 1902", the Romanian designation for the "76-мм дивизионная пушка образца 1902 года", "76.2 mm divisional gun model 1902") and the same gun reworked at the Reșița works in 1936 called "Tunul de câmp Schneider-Putilov Md.1902/36", the latter having a removable liner that allowed it to be converted to fire three types of ammunition - original Russian 76.2mm ammunition, the gun being designated "RF", French 75mm ammunition from the Mle.1897, named "FF" and, finally, french shells mated to the cartridge of the Romanian Krupp Md.1904 field gun from WW1, named "KF".
There was another earlier attempt at converting the Md.1902 guns by the Reșița works in 1925 which resulted in the "Tunul de câmp șemizat Md.1902/25" ("Field gun, relined, Md.1902/25") which had the ordnance code 20b, but very few were actually converted so I didn't include it.