George I think the bearing surfaces are bronze shims, the sliding plate is spring steel . Happy to be corrected as always.
The bronze bearings are replaceable items as they are subject to wear if not lubricated.

For Grumpy Pa - check there is no lateral movement of the blade, if so replace the shims for a smoother ride.
Very cheap even at Rutters grin2

2009 4/4 Henrietta
1999 Indigo Blue +8
2009 4/4 Sport Green prev
1993 Connaught Green +8 prev