Belgian M 1888-89 Experimental bayonet. (ABCN1074)(K0)(JN0)

Belgian experimental rifle, M 1888-89. Comblain rifle?. Serial number: 260 on crossguard. Superb bright finished fullered long blade with Belgian inspection mark FL in a trilob on the ricasso. Very long double edged tip.
Excellent+ bright finished pommel with blued oil drop shaped catch. T-slot. Crossguard opposite is marked with a tiny: L in circle. Very nice wooden grips fixed to the blade tang by screws and washers. Faint LD stamp on blade tang. There is a very little abuse around one of the screws. Beautiful bright finished crossguard with muzzle ring MRD 16,9 mm. and forward swept guillon. Ferrule is marked with a tiny: S in a diamant shape. 
Excellent black tooled leather scabbard with brass fittings and a round frog stud. All stitches intact and no dents to the fittings. Top mount is marked R in a circle and the chape: CD.
Throat is also marked CD. Finial is marked with another tiny R stamp.
Length: 564 mm.

Extremely rare and unique prototype bayonet in an Excellent+ condition, one of a serial of 3 different trial bayonets, all with the same hilt model. They differ in blade types, MRD and distance of the muzzle ring from the hilt. This is the flat blade type. There is also a T-shape type, MRD 15 mm. (ABCN 1072) and a cruciform blade type, MRD 17,4 mm. (ABCN 1073) known.
This model is the first one we have ever encountered.