As Bill posted, there was never any Remington #6 "Rolling Block" - they're all a tilting/pivoting block action.
It's just that many simply look at them externally, and assume they're rollers.
Numrich lists the rifle with the other rollers, God knows why.
It sounds like you need an entire Breechblock, Breechblock Thumbpiece, Breechblock Spring, a Breechblock Pin, a Hammer, and a firing pin w/ it's retaining pin.
BTW - The entire rifle's MSRP in 1902 was $5.00