Quoted from RETROCENGO:THIS is why JJP GnR Pinball playfields are Chipping, video link:
Those that own a GNR, maybe go to tour local hobby shop, and you can purchase brass round tubes and cut to size and slide onto the pinball post shaft before inserting onto playfield to get that snug fit within the wood.
Example of the brass tubes I'm talking about
https://www.hobbytools.com.au/metal-tube-round/