I agree with Alan. Not sure i understand large batch of marbles were produced from same batch of glass ???????? The vintage makers did not do a batch of colored glass. It was a24hr. a day seven days a week operation. The tank or furnace was refilled every 15-30 minutes to keep the glass level from getting low or keep near the same. The vintage makers did not do runs of a certian weight or time limit. They produced marbles according to sales in a continueous operation. Sparklers Popeyes and many many others of all makers were made over and over for years not a single batch or run. This was a big need for a recipe and weighing what went into the tank. If the same exact thing was done again ? Hopefully they got the same result. The same Sparkler or Popeye. Colors can be changed get low or run out anytime on purpose by mistake or production problems. We do see variations and hybrids. They may look the excat same but unless you witnessed it ? How can you be sure they were made near the same time ? Many marbles looking the exact same were made over different years. Not just a batch. I think stating same run may be sticking your neck out there. How can you prove same run ? Were you there when made? Just because they lookalike does not prove made the same hour day week or year. I think stating same run is sticking your neck out there. The special investor runs or batches at Jabo were a whole different operation than most all of the vintage machine mades. At a special investor run at Jabo. It was done by weight or time limits. When the limit was reached the machine was removed and the tank switched back to industrial marbles or shut down. The Jabo industrial marbles is usually a 24hr. a day seven days a week operation. They all look the same for days or weeks. Are they all the same run ?