M1 magazine markings? "1S"...

Hey guys,

Have a real nice all QHMC carbine. Went to the local show today to sell an '03, plenty lookers, no takers. Started lookin' around to drag some little something out. Went over to a parts guy and he had a big box of arsenal wrapped fifteen round carbine mags. Asked him if he had unwrapped any to see what the condition was and he said yes and they were all WWII and perfect.

Bought one for twenty five bucks. He was right about the condition. Unwrapped it and it is perfect as the day it was made. Beautiful blue.

Question...it is marked "1S" on the back. Both the one and S are serifed. Have "Warbaby" and checked every manufacturer's sub-contractor's magazine markings. Hit a dry hole. Before that I searched the internet for the marking with the same result.

Anybody know who made this mag? Very high quality, can't imagine any manufacturer could have made it better.

Thanks and regards for any info.

Death to tyrants,

Lancebear

Sure its not IS, for International Silver, which made a lot of replacement magazines?
M1 Carbine 15 rnd Magazines

Thanks Dnikkor, the "I" is missing the top right serif. Maybe a broken stamp was used, perfect NOS mag. Shoulda' looked at the stamp with my loupe last night.

Regards,

Lancebear