Mytilus trossulus?

[dave r]

I never got to those but intend to one day. I did visit the Viking Ships Museum when I went in the Summer, which was fantastic, and a Viking village, which was closed! 

Regarding C. glaucum, the best way of telling is the salinity of the habitat, they like lower salinity than edulis.  Also they are a lighter shell in weight and there are structural differences which can be found online.
I have found prettily coloured edulis here in England, but they tend to be young ones.

I never got to Copenhagen during Christmas but celebrated with a traditional Danish Christmas dinner in Hundested with a large group of people, it was really great. New year was unbelievable, they sure like their fireworks there. Many more than here on November the 5th!

Sorry to hear of your loss, I lost my Mother around 4 years ago now. Always a blow to lose someone close.
Dave