"Torpedo Shootings Indicator"

[Pisces]

Outside white-grey ring near the handle on the bottom seems to show "Kurs". The language looks Polish. Though I may be mistaken as I don't know a word in that language. And so it could have a different meaning than I expect.

It certainly looks like a variation of the attackdisk. But more like the American iswas-banjo disk, as it too had a square gridpattern on it. The German one is quite different. And yes, nice find on that very similar to Battenberg course indicator. On this one the bottom and right arm could be for range, bearing pointers. Then by rotating the underground disk (or upper ring-framework instead) one might be able to measure relative distance (and so calculate relative speed) and minimum relative distance.