Zeiss 7x50 Kriegsmarine armoured U-boat binoculars

An incredibly scarce pair of early to mid-war era Kriegsmarine 'smooth ocular' U-boat binoculars, still fitted with the very rarely seen original objective rubber armour and the early leather Benutzer lens cover. 
 
Over the last 10+ years of focussing on optics, we have encountered just 4 of these sets with the objective armour, specifically for use in the confines of a U-boat, still intact. 
 
They are very nicely and clearly inscribed with the Carl Zeiss Jena maker's logo, as well as the KM property markings which remain completely intact. The 'N' designation for Nordsee (North Sea Fleet) issued also present - and uniquely without any inventory number! 
 
The optics still remain functional and usable, but would also benefit from a clean / serivce if destined for any more serious use. 
 
A guaranteed full original, as found example that would make for a wonderful and unique display set within any KM and U-boat focussed collection!