What do the numbers05025167 mean on a Norman B50 acoustic guitar?

That's probably the 'serial number' of the guitar. Norman B50's were popular in the mid '90's. The maple side/back ones were about $800 new. I can only guess that the '050..' part means 'Model B50'. The rest are likely the date it was made. The '2' could mean it's a 'factory second' (with slight flaw). Check their site at normanguitars dotcom, or Seagull Guitars Canada.