A couple more thoughts/observations on the subject…..In looking for vintage freewheels, it is always helpful to know if they have standard or narrow spacing if a 6 speed…( narrow being a 6 speed freewheel designed to fit in the space of a 5 speed, I.e. a 120 mm rear hub). You may come across a Shimano Dura Ace freewheel. These were probably the models with the highest level of precision machining of any freewheel body ever made. You may also come across a SunTour Winner. These freewheels also featured very precise bodies. There was a less expensive SunTour Perfect model which was not bad at all. In general, the Japanese freewheels seemed to have softer cogs and didn’t wear quite as well as say Regina or Maillard (Sachs). I would look at these carefully for cog wear as this far down the road wear is VERY likely to be a factor.