Yeah, these cheap made guns have those problems. I hope that is the only problem you encounter with this gun.
These guns are too expensive to have these problems, however, IMHO, poor design and cheap manufacture is a fact of life with Pedersoli guns.
The nose cap is most likely cast bronze, so it will be brittle. You MIGHT get away with annealing the nose cap by heating it to an even deep blue and quench in room temp water.
The question that has come into my mind is; is this gap only at the back of the nosecap, or does it run the full length of the cap? Bending the nosecap near the front will certainly induce a lot of stress in the area of the solid end cap, so to be honest, I don't know if bending the nose cap is doable. And, knowing Pedersoli's quality control, any new nose cap won't be any better.
If this gun was bought localy, I suggest you return it.
If you decide to keep it, look it over closely, are there any other unsightly wood to metal gaps? How about the lock? Does it fit properly? If a flint gun, is the touch hole located at the top center of the pan? If cap, does the hammer strike the nipple correctly. I suggest removing the TH liner,or the drum and check the length of threads to insure the liner or threaded part of the drum does not extend into the funky little patent breech.
The length of the liner, or threaded part of the drum should be the same length as the thickness of the breech/barrel.
There are other issues with these guns too, but they are beyond the scope of this thread.
Good luck,
J.D.