Any idea who the maker of this pocket watch movement is? it is in a 56mm case marked with a crown and below that DKB with an arrow through it. No markings on the movement and it looks to be of good quality but is it a private label movement that is impossible to ID? I think the engraving on the dust cover is in German or Swiss? It does appear to have some characteristics of some high quality makers but can't find a match. Longines is the closest match I have found but still has quite a few differences. I will keep looking but any ID help is appreciated.