1275 Reusable Main and Rod bearing nuts? Freeze and Galley Plugs?

The nuts for the main and rod bearing blocks on the 1275 have no locking tabs 
or cotter pins. They appear to be "Nylok" or something like that. Should 
these be replaced?

How does one replace the galley plugs and freeze plugs?

At the relatively low price for a new oil pump, seems to make sense to just 
replace it. Yes or No?

David Oliner
60 Bugeye
67 TR 4A