U.S.Marine Corps four bladed pocket knife


At a local gun show I picked up three U.S.Marine Corps marked four bladed pocket knives, these are silver. We were issued the same pocket knife except just marked U.S. when I was in the Corps. We were also issued black handled two blade pocket with the nomenclature of TL-29. The silver pocket knives we called TL-28's. I am being told this is the wrong nomenclature. If that is the case what would be the proper nomenclature? Thanks for any assistance.

USMC TL-28.jpg

The five below, I was issued over the years.
TL's Issued.jpg