UBB.threads Forums Edged Weapons The BCN Bayonet Forum unknown bayonet to me.

A friend of mine has this bayonet form his Grandfather and I need help on IDing it. Bayonet has 2872 stamped on cross-guard and on the brass frog stud. The other photo is of the spine of the blade next to the cross guard (looks like a capital N in a box. The scabbard is leather with a brass top and bottom. Blade is 11 3/4" the hole in the cross guard is 15mm. I looked in Janzen book but unsure.