Case material is silver colored metal that is not chrome and has resisted the the elements much better than the normal chrome plated ovr base metal cases of typical Type A-11 cases. The case measures 30mm or 1 1/8 inch diameter w/o crown, 36.0mm lug-lug, 16.0mm between lugs. The stainless steel case back is stamped:
BULOVA WATCH CO.
21/11/2011 Edited case material to reflect new support data indicating numerous instances of silver cased military issued Type A-11 WWII era hack watches.
This Type A-11 watch meets all of the requirements of military specification no. 94-27834 dated 1941, Watch Navigation, Type A-11 (Hack).
There are no military specified plating requirements in mil-spec 94-27834. Pate finish was left to the manufacturer. Big bad Bulova move. I don't wonder why so many Bulova chrome plated WWII era Type A-11 & ORD watch movements are re-cased. The auction market is flooded with re-cased watches & sold as Pilot watches.