First which model and engine? I assume it’s the G4MII since it’s a 57
The camshaft its self typically holds up well. I still have the original in my 59 and back in the day these engines were supposed to do up to 40k miles before a topend rebuild.
The camshaft has a ball bearing at the driven end and a bronze bush at the remote end. I’d replace the ball bearings, any bearing shop will be able to order it and replace the bronze bush with Delrin, blue Nylatrol GSM or Nyliol. If the bush gets sloppy it leads to a lot of wear.
The followers/push rods are made from some kind of an alloy called Duralumin. I was told that this had a case hardening process and coating applied - kind of similar to titanium valves on modern engines – and when this wears it caused problems but that should not wear the lobes.
You can also check with Fireball Coatings and see if they can do a Moly coating on the camshaft for you instead
http://www.fireballcoatings.com
I have also had good success running oils for diesel engines like RotellaT.
PM me with your email address and I’ll send you a great PDF on the engine specs, tolerances and rebuild procedures.