Original WWII U.S. Army Air Force B16 Liquid Compass with Mounting Bracket Russian Army Question: There are some letters/numbers

Question: There are some letters/numbers stamped into the inside dome of my WWI helmet

For more than a century and a half

FREEMAN and LONDON on the iron barrel along with London proof marks

CARBON DIOXIDE FIRE EXTINGUISHER

Original WWII U.S. Army Air Force B16 Liquid Compass with Mounting Bracket Russian Army Question: There are some letters/numbersA great old WWII aircraft compass by Bendix. This piece is liquid filled and still works. It is contained in the original instrument panel bracket. Top data plate reads: ORDER NO AC 26968 MFR'S PART NO 1818 1 A SPEC NO 94 27807 BENDIX AVIATION CORPORATION PIONEER INSTRUMENT CORP BENDIX NEW JERSEY USA Front data plate reads: A. C. U. S ARMY TYPE B16 SER NO AC 41 56124