Grimjim,
Being an ITALIAN VETTERLI VITALI and not a Swiss Vetterli would indicate it is still in the 10.4X47R chambering but it would be best to take a chamber cast first to make sure.
Then if it is all is not lost. Loading dies, although expensive, are available from C&H at a cost (as per their website) of $109.00 + Shipping. I have gotten dies for oddball calipes in the past and they are nice dies.
I believe the bullet is a "healed" bullet cast with a .410 base that goes into the case. The bullet base expands to .429 or .430 (bore diameter) to grab the rifling when it is fired. If you try to use a .429 bullet it will expand the case so much it will not go into the the throat of the rifle (you will not be able to chamber it). I beleive you can have lee custom make you a bullet mold like this, there may be others custome making these molds also. You will need to cast the bullets from relatively soft lead or they will not expand to fill the rifling and you will get leading and poor accuracy.
The brass can be made, again as I remember, out of .348 Winchester brass.
The above is probably not for someone just starting out in reloading as "making brass" from another caliber can be challenging. Buffalo arms does sell 10.4X47R Italian Vertterli brass for about $2.50 a round. So you can forgo making brass. They also offer a .41 Colt .410 healed bulled that "may" work in the Italian Vetterli , it would be worth a try I guess. They are about $15/100.
One final thought, if you would like something that you don't need to spend an arm and a leg on for loading dies drop me a note. I might be willing to swap you one of my Italian Vetterli's in 6.5 Carcano for the the one you have. You would still need to load for it as I would NOT shoot modern/jacketed in it, but you can get dies from Lee for about $30.00 and brass is fairly readily available. Just a thought...
Take care...
DonT