Help me identify these knives..please

[melman66]

Single blade is silver colored. Sorry for the poor quality pic

I would like to know more about these two knives. The only info I have was a piece of paper that said, "FBI Special agent..then the word infantryman" . The single blade is approx. 1 1/2" long and a little less than 4" open. The twin blade infantryman knife has two 1" blades and measures approx. 4 1/2" when opened. Thank you for any help you can give.

[TripleF]

Any markings on the tangs (at base of knife blade)?

How'd you come across them if I may ask? They look like something you'd see at a privately owned convenient store..

[melman66]

After further examination, I did see some letters on the tang of the twin blade. The first letter is tough to make. It looks like DEFFIE. But it really is hard for me to see clearly. I will keep trying. Hope this helps. My great- grandfather left them for me and I want to know as much as I can about them..thanks again

[knife7knut]

After further examination, I did see some letters on the tang of the twin blade. The first letter is tough to make. It looks like DEFFIE. But it really is hard for me to see clearly. I will keep trying. Hope this helps. My great- grandfather left them for me and I want to know as much as I can about them..thanks again

It probably says,"Sheffield Steel".I have a couple of these that have that stamping but I don't think they were made in England.They are very reminiscent of Imperial skeleton knives of which I have many.
The second one may have been made by Miller Brothers or George Wostenholm or any one of many manufacturers.Check to see if the bail has any markings;sometimes they are marked with either the maker's name or the gold content if they are precious metal.