455634R1 for regular
457608R1 for chrome plated
991015R91 for standard rivets
407039R91 for tubular rivets
From personal experience, it's a lot easier to change out the whole guard (MC4043Z for outside, MC2041Z for rest of bar) than it is to change ledger plates.
These numbers are still available and active and if anybody tells you otherwise, I'm a Case IH parts guy so I'd like to think I know what I'm talking about.