Left-to-right:
#15-No thong hole: 1968-69
#15-Thin lugs- Seperate "S": 1973
#1-6"-Brown button:late 60's
#15-Solingen SS-Flatground including handle: 1972 * Schulz carry
Camillus MkII-Rehandled by Pete in "Old Yeller" *Schulz carry
#2-8"- Re-handle recently: In country 1970-71
Fairburn-Sykes, sold by RMK and sheathed in black JRB-1969-70

I have more VietNam "ERA" but all of these served, in country.
Stay Sharp,
Capt. Chris