As I understand the rolling block(I had a #1), they have 2 blocks, each with a pin or rod on which they rotate. The rods or pins are held in holes on each side of the vertical sides of the action itself.
The front block holds the ctg. inside the chamber & caries the firing pin, while the second block, has the front rounded surface rolling under the rear edge of the front block & acting as the action's locking lug.
The Stevens Favourite is very similar to the Ballard action, in that the block is cam'd on the lever's linkage to hold the ctg. in the chamber against back thrust.
This is as I understand these actions. Hope my explanation is sufficient and I managed to get them right. If not, open for correction(s).