No....the staff is for the Mod.18. In the 2nd photo above you see the rubber tip end of the staff. You un-screw from the knurled brass piece and remove the tip. Remove the butt end piece on the mod. 18 and then screw the staff onto the knife. Makes a spear. It is a very neat piece that has been around for a while now. Byrd's first staffs came in a polished finish. Later he started making them in black. As I understand they are not that easy to get any longer.
FYI Byrd worked for Randall at one time and his job was making the tube end of the 18's. IIRC. I only had one 18 with a brass butt cap and I sold it some time ago.