It has been drawn to my attention that it was not an uncommon glassworks practise to produce more than required for a limited edition. This allowing for seconds and breakage to ensure that the full edition quota could be produced. But bear in mind not all limited editions were necessarily produced to the full quantity - amply illustrated by Charlton which often shows actual numbers made were below the full edition for Caithness.
In general the trade prices was 50% and seconds could be sold above that price in the factory shop.
So I guess it is fair to say that a considerable number of seconds were simply surplus to the edition but perfect. So if you are puzzled as to why your second looks so good, you know that it probably is a perfect piece.
Once word spreads, will we get listings on eBay differentiating between perfect seconds and second seconds
will that result in a 3 tier market? Well with the wide range of prices achieved for any single item I guess it would make little difference other than perhaps drawing attention to the really flawed items - which would themselves be an interesting study area as they give an indication of the quality control and skills to hand.