I had the Org. Nitro R-2 that's from back in late 90's. Symmetrical core, Solid. I believe there was also a re-release version R-2 Classic about the mid 2000's. It came sanded was a good med. condition ball back then. I liked it and used it a lot.
The Stingers are from early 2000's, Sym. core there are 2 -2 piece ones the low flare is a particle ball and the low flare pearl is a reactive pearl.
Now I had the org. Blue Faball Hammer back in the late 90's, (Norm Dukes main ball back then.) Good urethane ball. The Faball hammers were great ball's, the org. burgundy hammer is one of the best urethane balls.
You didn't get hurt for $25 the Nitro and hammer are worth that.
Bookmarks