I got one when I bought my 1894D Cowboy Carbine Limited (CCL) in 2000. Can't remember if it was included in the box from the factory or just a pot sweetner from the dealer I bought it from. I know he did toss in a couple of boxes of 44-40 ammo in on the deal. I still have the buckle on my pistol belt. Also got a set of Marlin screwdriver tips then too.
ETA: I'm thinking I remember seeing them advertised on the Marlin website for sale about the same time.