Combination knife/gun weapons have been popular gadgets for literally hundreds of years, and this is one of the nicest examples I have yet seen. This sort of thing is usually very flimsy, and not particularly well made. This one, however, has a blade which locks in place securely and would seem to be quite practical. The firearm part is also unique, in that it uses a needle fire bolt action mechanism. This is a tiny copy of the French military Chassepot system, complete with intact needle and obturator.
And, of course, since it is French the trigger is a corkscrew.