Tomorrow will mark the 100th anniversary of one of the most important U-Boat successes (and one of the greatest tragedies for Britain during WWI). I'll be doing a little model work Monday, as my own minor commemoration - it will be posted later.
Regarding collars, the game goes berserk when you make even minor changes to the human torsos, so I don't think collared shirts are possible. Capt. Cox is one of the few modders who could possibly do it, and I have not heard from him for a while.