ID. 5 Shot German Revolver

Have 5 shot WW2 era revolver,6.35 CAL.Very small,4" OAL,2.75" OAH. Folding trigger, hammerless, Hex barrel 1.375" long. Markings: LH side of frame,shield with X inside and what looks like helment from a suit of armor on top edge of shield, circle with R inside and flame on top edge of circle,letter 'N'and CAL 6.35. Barrel:LH side Circle with R inside and flame on top edge of circle, RH top side letter G with ECOinside.Leather holster resembles US calvary flap holster. Would appreciate any information on ID,origin,etc..