I don't really have much knowledge about Submarine's and such, but that museum sure looks interesting. Might want to pay a visit, when I'm in Finland meremuuseum.ee/en/
LOOK AT HER. LOOK AT HER BLUESKY!
Clearly based on the U Class, but adapted for Baltic ops. That's an icebreaker bow (which makes her lines filth af) and she's rigged for minelaying above and below, hence the sidepods. Her tail is pure U though.
I would marry this boat. She is utterly gorgeous.