Let me try some answers, and I’m not really sure: DEF means “defective” and normally with tracers that means that they fail to light. I have only seen one or two lots of other “defective” tracer lots. The “failure to light” normally means that the lot of ammunition is used in training as a substitute for ball ammunition. You would have to look at the ammunition data card and or the ammunition lot card to determine if the lot has actually been restricted to training use only (as ball ammunition) and normally restricted to CONUS use only. while we have no documentation, we can be very confident that this lot was restricted. I think the “AND” is not the manufacturer, but the arsenal that repacked this ammo–I’m thinking Anniston Ammunition Depot in January of 1952, but again not sure.
Hope this helps,