Welcome aboard! I'm not the expert, but Dougie has found that while emblems were discouraged, no real effort was made to stop them. U 201 altered theirs through the years, and I'm sure were using in 1944. Download Dougie's Wolfpack from the AMP website "BOOKS" section, but I think you are plenty safe with the uboat.net suggestion. The emblem would be separate to the flotilla, and probably changed a lot.