I see the nameplate says made in England and then the German engine - I guess it is not US military - I should have been more observant. Is there a voltage regulator with a number on it? I think all stamfords are PMG excited, so it should not need battery voltage. I think you could get a new regulator and or test procedures pretty easy. I have actually left a message with a contact to see if I can get a regulator pn spec - I see it says 32V excite and 1.3 amps on the plate.