Well, technically, no soldier of officer would be wearing any SSI during wartime with the exception of a few divisions later in the war...is this what you are referring to?

I like where 'atb' is going with this and agree with 99.999% of what he said. Also looks like the 28 over stamped something else and maybe the 78 is part of that prior marking? So maybe it was Company F and the 28 is the soldiers ID?

Yes these were included in Colts branded pen flare kits early on and availableseparately from penguin. I have seen them numerous times but they are not super common to see now a days unless you are into VN era survival equipment or in the flare/gun collector communities. These cartridges are like 2x larger than the flares and go over the pen flare launcher. They had issues with striking the primers as they didn't screw into the pen, they just were pressed over top. If it wasn't seated right it wouldn't fire or result in a light primer strike, which sometimes would result in a cartridge that would not fire if attempted to use it again. Neat little item from the VN era. 

I may be wrong but I think that Meyer mark was used in the 60s and 70s

It is more than likely made from a military blade (Ka-Bar or some other of the sort). That it came from a WW II Vet to his S-I-L with nothing else for provenance, one could jump to the conclusion that it is "theater made".  I have a feeling if I could get under the ringed guard, there might be a makers mark there or not. My WW II Camillus, NY, USMC Ka-Bar is only marked on the guard (which in this case would be gone). 

There needs to be a better name for modified military knives with no history or evidence they were made during a "Theater of War".  Without the knife in hand I can not say for sure, but this knife has a blade that looks very used, compared to the condition of the handle.  "Theater Made Knives" with no verifiable history, could have been made in a Jr High Shop class.  I did with a knife my WW2 Veteran Grandfather gave me in 1979.  I also refinished a wooden rifle stock the next year in Wood Shop".  Boy have times changed. Never the less, this knife is unique, but without evidence that it was actually modified during a "Theater of War", suggestions on what to call these?

With the computer-generated embroidery I would say you are looking at a flash made within the last five years or so.   Allan

Scott C,   Cool story. I think your flight helmet is a HGU-56 but I might be wrong. I worked with the C-130 FST at Cherry Point for about 10yrs as a Draftsman. We did everything from SATCOM to the Fat Albert Paint Scheme.

Hello,           Can anyone give an approximate date for this flash? I don't think it's very old. Just a little confused with the edge which seems flatter than the usual merrowed edge.   The bars are M9 Meyer which I'm sure pre -date the flash.   Thanks Billyh

That F.28.78. could also be another unit to which the holster belonged. I would think a former unit's marking would have been marked out, though.