Not a concern , your right this happens during manufacturing and many NOS tubes have bad Oxidation on pins , you can of course clean these up carefully.
Tube pin question?
Many tubes I've seen have what appear to be discolored/burnt pins. These have all been steel pins not gold plated ones. Was this caused during manufacturing? I imagine everything gets pretty hot when the glass was melted to create the vacuum. Concern or not a concern? Thanks!