Hello Schaerbeek, this is an interesting find. I haven't seen one of these before... What size is it?
It looks kind of similar to one I have up on ebay now: http://www.ebay.com/itm/170914048928?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
Which has a diameter of 42cm.
The submarine plaque you have has more detail on it though. Where did you find it? Did you see any more than just the one of them?
Also what do people think of the brass soviet train plaques up on ebay at the moment from a Russian seller? (http://www.ebay.com/itm/ANTIQUE-STEAM-LOCOMOTIVE-Coat-of-arms-USSR-Soviet-Russian-Metal-Plaque-LOOK-/251104672599?pt=Architectural_Garden&hash=item3a77013b57)
They are a bit pricey. I cannot figure out if they are legitimate originals or replicas, since all of these train plaques were made of aluminium, not brass, so what do people think?