Opinion on this possible Kriegsmarine coat

[KwK36]

Please, your opinion on this heavy coat. My brother got it years ago from an old friend, supposedly this is an old U-Boat coat. Yes, it makes for a great story. I can tell you that it is very heavy. No markings inside except for a tag with 55 sewn in, most likely it's size. Heavy wool interior and as you can see multiple pockets. I'll also post pictures of a button that fell off a few years back.
Thank you

[KwK36]

Coat continued

As promised, one of the missing coat buttons. Manufactured by Overhoff with some kind of unusual symbol below. Real nice anchor button.

[km-spain]

Hello, nice original deck crew leather jacket, as you say used by u-boot men, but not only for them, also was used by some surface vessels men. The button is marker with maker logo, OLC

[-Ray-]

Very fine example typically intended for topside employment. Readily agree with Eduardo's additional comments above

-Ray-