Is this correct

[lawman0210]

After closer inspection on a new bayonet I see I have an M9 made by Buck for commercial use built in 1987. It has Buck 188 U.S > on one side of the blade M9 Phrobis III U.S.A on the other side, and has the phrobis dolphin logo on the hand guard. The scabbard doe NOT have a mag pouch, has the sharpening stone, danger area warning in yellow and the phrobis logo under the sharpening stone. Is this all period correct or has the pouch been lost or has the bayonet been switched to a different scabbard. One last thing I see people listing M9's as 3 line and 4 line. I originally thought 3 line meant blade said M9, Phrobis III, U.S.A and 4 line meant that Pat. Pending was added and thus making it a 4 line. Is this correct or am I missing something. Other then the wording on the blades I really don't see anything different in any of these M9's other then the newer lan-cays look like a cheaper quality