R Tank Mark on Push Dagger any info would help

[Kramersknife]

Hello I am new to this board.
I have had no luck finding anything about this knife other than the Wing was added after the knife was made as the knife is a true piece of craftsmanship and the wing looks not as good as it should being such a nice knife. Only has a "R" on tang and on the sheath. Handle is aluminum w/ wood plugs
Does anyone know who the maker is? I was told its Vietnam era and possibly carried there or inabouts the military somewhere.
Any help would be appreciated Thank you

[Madmarco]

Can't help with identifying your knife K.K., but to AAPK, and stick around as someone will be along who can help you!