I have never heard this called panzer troop ring, I would have said just a pp skull pattern. a top- down shot would be helpful. But what I see here is an odd placement for the silver content and "laurins" mark. Laurin mark looks odd to me (generally just a stamp "Ln" in script) a jewlers mark of high quality. It looks thick, but I would draw it as inconclusive for me based on these pix. Regardless, for 350� it better be unquestionable and a rare pattern. Wait for more opinions.