Just let me know if you need/want them. BTW, you might check with Mike M at Flying Dragon, too. I think those B25s and B28s use copies of the Diana sight. Might be they use the same size ball in them.
That little ball may have jumped out on the floor while you were unwrapping the gun. So it may have made the great escape to never never land, lol. And as tiny as it is you never would have heard it hit the floor or anything if it did escape that way.
Um, just had a thought here. Since you found the one ball in the bag, it's possible that the second ball stayed in the bag too and might have found it's way inside the gun. Might not hurt to take the action out of the stock and give things a good going over before you shoot it. And be sure to give the cocking slot a really good look inside, too. If there's any grease on the mainspring that little ball could be stuck to it. Myself, I'm not sure I'd want to shoot the gun until I was sure that ball wasn't inside the action somewhere.
"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"