Three rare 3,7 cm Skoda shell cases

[Hoeksel]

I am helping a collector with several ID's. Shown are 3 rare shell case head stamps. I am looking for verification/help for the ID and explain some abbreviations.

1 - I suspect a Czech made Bulgarian 3,7 cm Skoda M1937. Bulgaria is pretty convincing as they often used "D" to represent "L" as in "L/48". The Skoda 3,7 cm M1937 is L/47.8 and known to be bought by Bulgaria. Does anybody know the meaning of "CA", "S1" (probably S indicates lot) and "u.c."?

2 - Another Czech made Bulgarian 3,7 cm Skoda M1937. Any clarification about the meaning of the Cyrillic marks is appreciated. Notice the German made primer.

3 - Czech made under German occupation, a 3,7 cm Skoda M1938. It should be for the 3,7 cm M1938 A7 tank gun I assume. The primer has an "S" which is uncommon and possibly comparable to the "S" on the shown Bulgarian 3,7 cm M1937 (#1). I do not know the meaning of "T.K." nor does the logo above 1941 ring a bell. Also not sure for which country this is.....

Thanks in advance, and even if nothing get's ID-ed, these head stamps are too cool not to share .

 

[AKON_]

ad1) the cartridge goes into the 37mm insert barrel for Croatia, used in the navy.
Here is a preview of the ballistic tables.
Where is the designation ,,u.c.,,,
Vo-700m/s
M - 825g,,
Typ : Tempirna dimna granata,,
Here is a preview of the ballistic tables. Where is the designation ,,u.c.,,,

Továrna na nábojky a kovové zboží, akc. spol. Rokycany Patronen-Hülsen- und Metallwarenfabrik A. G. Rokitzan Rokycanská zbrojovka Kapslovna, Kovohutě Rokycany, akcie

37mm skoda shell

Hello, looking for info about this 3.7cm skoda shell My guess goes to a czek made for export, may be 4cm Z1, ex Austro Hungarian 3.7cm L/70 navy gun used by Jugo as 37/67. something similar here...

www.bocn.co.uk