Part of 3,7cm C/30 dummy/drill round?

[Hoeksel]

I have this item that has the same rim diameter and rim thickness as a 3,7cm C/30 case. This way of headstamp I have not seen before on a 3,7 cm C/30 case but it does resemble the stamping methods of 8,8 cm cases of the same period. So I assume the headstamp is normal, just earlier than I have in my collection till now. The extra stamped "E" above the year of manufacture is also typical for 3,7 cm C/30 cases.

I think I made a mis-buy (hoped to have something different) since it is clearly cut-down. Ah well, you need to take a risk now and then. But there are 2 things I do not really get.

1) The case is filled with wood.
2) Although it seems cut-down, you can see some tapering.

These 2 facts make me wonder if this might be a part brass/part wood dummy/drill round of some kind? The height is 137,1 mm and the rim is 58,0 mm with a 4,15 mm thickness.

Does anybody recognize this?

 

[EOD]

It is entirely possible that this was a dummy/drill cartridge since there are several navy dummies which are made in naval ammunition workshops (Marine-Munitionsanstalten) from regular components. The 37mm dummy C/30 I had seen before had a regular case and a wooden projectile was fixed inside the case with copper nails or rivets. It seems that every workshop had it's own style of making dummies.