The bayonet should fit up inside the slot in the correct original wood stock for a spike or blade bayonet version.
Spike bayonets are often installed incorrectly; 50/50 chance of getting it correct/incorrect. Staking marks can be lined up even if they're no longer untouched since staking. The flat side should be out when the bayonet is folded into the stock groove, i.e., when you grasp the foreend you don’t have a ridge from the bayonet digging into your support hand.