I have seen them on the anti gun auction site about once every 2 or 3 weeks.
I suspect that Deer Creek (which purchased the left over CVA side lock gun parts inventory) has them as well. I am fairly certain it is the same nose cap on the kentucky rifle they sold.
Lastly, I believe that traditions still sells that pistol in kit form and the nose cap may be available from traditions, although their parts dept is very hard to get through to.
I am currently bidding on such a pistol on-line and will not need the nose cap, if I win. You would be welcome to it IF I win. (I intend to cut the stock back and add an underrib and larger ram rod, to make a mountain style pistol)