It would be good to have more details on the year of the gun. I say that because there has been variation in how they go about the chamber setup in the cylinders. I have a 76 Ameri Sao Paola (sp?) that has tapered chamber. It won't shave lead. .454 ball works well but it came with .457 (which will go in, harder though).
I don't know rodwah as I am pretty new to the forum.
My preference is to listg what is my opinion and try to present the other side if its in an area of disagreement.
My guess is the Pietta is intended for .454 ball. I have seen lower sizes listed but both Pietta and Uberti of recent vintage list .454. As was noted, you want a reasonable size band of lead (literately a band forms as the ball gets squeezed down if the right size).
The need for lube on the end or a wad is contentious at best. I believe a solid case has been made that as long as the ball is the right size, there is zero need for a wad or lube.
One caveat is that the chamber on each cylinder is checked (ball into said chambers, driven out, band checked to see if its there). There is a chance you get an oval chamber (problems happen) an if its oval, it won't seal.
The newer guns shave lead rings as a good indicator but the 76 ASP did not, it was tapered. I don't know how far back you go to when that was a standard. Keep in mind all those Italian makers have shifted and shuffled and Uberti and Pietta are the remaining ones. Both have inheritance in others such as ASM and ASP.
I keep my cleaning simple. For an Open Top, pull the barrel assembly off, into the sink or a pan, run a nylon brush thoru8hg it (any modern dish soap) and its clean as a whistle. Yes you get some spots of surface rust - I dry mine in a good type dryer (Walamert for drying apple slices and such). Mine is for shells out of a wet cleaning process but they are all the same.
In that case the Balistroll may work to keep the rust off, I may play with it, but have not found it a real issues either. I don't let the rear assembly anywhere close to water. I can clean it and per 45D have it sealed with synthetic grease. I do need to clean the hammer slot and hammer off from time to time but its a simple scraping process.
I have not seen Number 10 caps ever (3 years of shooting BP now?). I take what I can get. Given a choice the RSW 1075 fit the cones. Not sure what a magnum cap is, still learning.
As for screwdrivers, my choice is a multi bit called Megapro (you can get them at Grainger. I have 3 types, HVAC, Electrical forget what the third is. I am picky about tools as I mechaniced since I was 18. I hate multi tools. These have outstanding bits. Hardened, right shape, many choices of slot and philips. You have to look at the choices for the max number of slot bits. I forget which one has most of the slot type. You likely do not need the other bit types but I used them for scope bases, scope rings and other odds and ends of a techg life.
Slix Springs makes the best Nipple wrench. I did ot think it was the right shape and I was wrong, fits to hand nicely. Also very hard to it does not curl the edges like the cheap ones do.
I do not use any lube on the Nipples. I pull them generaly to clena the cylinder (same soap and water) and got to be a pain. They might stick if left too long but they get pulled often enough dry has not been an issue.
The disk would be referred to as a Lubed Wad. I use them as a spacer to see if it shoot better (aka filler). Mixed on that. I also shoot a bit of .451 ball and I use them under that. .451 in my chambers does seal but its a thin band and I don't trust it, ergo the Wad is a prevention use in that case for chain fire.