Lefaucheux with blade
That gun is indeed a rarity.
The signature " Ivr E. Lefaucheux Paris-Breveté SGDG" in an oval on the trigger block prooves it was produced in the inventor's own shop in Paris, rue Vivienne n° 17. You will probably find a stamp LF under crown somewhere else on the gun. I guess it is in the 7mm-caliber.
It is what we usually call the "second type", with a rather square shaped grip. This group of revolvers have always a more complicated mechanism and are very well finished. It looks like Eugène Lefaucheux has reserved that model for luxury weapons only.
The elaborate engraving on this one, also on the dagger, leads me to think that the gun was made on special order and was a gift or a commemorative rather than a usual defence weapon. As a matter of fact, the dagger is not really effective and more decorative than on the most other dagger-revolvers.
The fact that there is no spur to the hammer indicates that the gun is double-action only; this could be an indication that it has been made on special order for a British client. The British market seems to have affectionate revolvers in double-action only; they produced many pinfire and percussion revolvers having no single-action features (cfr Robert Adams, Adams & Deane, Durs Egg...).
Dagger-revolvers (also called "cutlass pistol") are very impressive, but they always proved less effective. The cutlass is usually too heavy and too long for a good aiming and rapid firing, while the revolver itself is not an ideal grip to the knife. Various gunmakers produced some, but never in great numbers.
In the book "Systeme Lefaucheux" by Chris Curtis, page 58, you will find a picture of another one produced by Dumonthier. It is quite identical to yours, except for the dagger lemmet which is not engraved.
There is an important part missing on your revolver. There is no ejector rod. Normally these guns were delivered with a strong scabbard for the dagger, to which the ejector rod was attached.
Marcel
