Camillus fixed blade ID

[whooknew]

Hi,
I could use some help identifying the model/year of this knife.
The knife belonged to a friend who served in the Australian defence force.

it is marked
U.S.
CAMILLUS

has a 7 inch blade, 12in overall.
The handle and sheath are very dark brown?
Have included a picture below, any info would be appreciated.
thanks

 

[coondog108]

Got mine while with USAF in 1972, they called it a "trench knife" check out http://www.collectors-of-camillus.us/

 

[CAMCO]

This is a model #5684 Marine Combat knife made 1974-1989.

Tom Williams