Wanted: Shimano 600

Obviously not geeky enough as actually there are more variants.
The original 600 series was not SIS, nor was the following series either. Indexing only came in with (effectively) the 4th production series of Shimano 600 (though they did overlap somewhat)

So you missed out original 6100 series black lettering, friction shift only
6207 series (600EX) black lettering and again friction shifting only

You could use the 6207 rear derailleur with an index system if you were very accurate with setting it up.
The 'aero' series was 6300, the first 6 speed index series was 6208.

Sorry to be a Shimano geek, but there are four versions of 600, listed here from cheap to pricey:

• original plain 600 with black "S.I.S" rear derailleur
  
• 600 tricolour
  
• 600 Arabesque (EX)
  
• 600 AX, parts have blue logos and 80s "aero" geometry