Thanks a lot for your reply!
Too bad you don`t have any other examples with this kind of markings!
My suspicion is that this shell in particular was, at one point, refurbished by the Romanians and then again refurbished by the Germans (by applying the German markings over the Romanian paint). I will elaborate below.
According to D435/2b "Die Munition der Beutegeschütze und Werfer" from 1943, German markings for captured ammo did not change the paint and used exactly what the Russians were using - meaning either unpainted and greased shells, or light gray coloured. This color scheme is exactly what the Russians were using and it is confirmed by Russian manual drawings. Of course, the new German designation for the round had to be marked - in your case it is 7,62cm Sprgr. Patr. 284 (r) - Which is the UOF-354M round using the OF-350 shell for the 1902/30 field gun.
On another note, from the photos you posted it seems to me that your shell is painted yellow with black markings. As per the above, this does not correspond to either German or Russian markings. In the Romanian artillery coding for markings and painting, HE shells are painted yellow (shades vary from pale yellow to bright yellow depending on stocks, relic preservation in the ground, etc.) and usually have the painted markings in black using a specific sequence that goes
No/Nr. X [Order number of the shell type for the specific gun]
YY-ZZ or Q.QQQ [lot number and year of manufacture on refurbished shells or weight of the projectile in grams for new production]
AA-BB-CC [Code for the corresponding gun firing the shell, A is the type of artillery, B is the caliber and C is the order number of the specific model of gun]
DD-EE-FF [Explosive filling used, lot number and filling year]
On top of that, from archival data regarding some test firing we know that there was a 76,2mm HE shell captured from the Russians designated “No.12” , and although we don`t know exactly what model it was, considering all of the above I think we can conclude that No.12 is the OF-250 and that your shell is marked according to the Romanian marking codes.
Your shell seems to break the rule a bit by having the lot and year numbers on two different rows rather than being on the same row. Other than that, all other elements fit. Also, please check if you can read anything else on the fourth row. It should read something like
TC-76[SUP]2[/SUP]-Nr. XX, where XX should be in the 22-29 range.
I know this is maybe complicated to follow, but I hope you understand my point.
Attached:
-Russian manual drawing with OF-350, with grey paint and specific markings
-German manual drawing with painting specifications that translate “unpainted and greased shells, or light gray coloured”
-Romanian document showing the No.12 shell.
-Example of Romanian yellow paints for HE shells
-Example of typical Romanian marking on shell.



