Alox also purchased marbles from Ravenswood so it's possible that is how the PBs wound up in Alox packaging. And PBs are not specifically mentioned in any of the Master or Alox paperwork AFAIK. Although there is paperwork showing that Master sold large marbles to Alox, which is pretty obvious if you look at the Alox bags with large Sunbursts in them. It also seems odd that the PBs were packaged by and labelled as Ravenswoods if they were made by Master (or Akro for that matter, which I think has pretty well been ruled out). Assuming the PBs were produced to supply the maker of the wooden PB-Babe toy (too lazy at the moment to find their name), it seems odd that Ravenswood would serve as a middle man - putting Master marbles in Ravenswood packaging. The fact that they are entirely unlike any other marble Ravenswood produced sure would have been obvious to the toy producer who would likely have gone straight to the source to purchase them rather than buying them through Ravenswood.
I think Ron ultimately decided that he believed the employees (or offspring) who told him that they were made by Ravenswood, rather than the one who told him that Ravenswood didn't produce them. And the story about them being made at the pottery company (your right, it was very close to the Ravenswood site) helped explain that discrepancy. I think it was an offspring of a Ravenswood employee who told him that their father made them at the pottery factory and remembered him bringing home warm ones.
Of course, a lot of confusion stems from the fact that the PB marbles are found in both mesh and poly bags that were apparently filled long after the marbles were made (the ones with the "Akro" card attached), and many Alox bags were back-filled at a later date too. It seems likely to me that the person(s) who found the cache of PBs was packing them in any old bags/headers they could find, and also in those bags labelled "Genuine Old Fashioned Marbles", which also included typical Ravenswoods.
Ron and I discussed the origins of these marbles on numerous occasions over many years. I do not recall him citing any one specific reason that ultimately caused him to settle on the Ravenswood/pottery idea - I think it was likely an accumulation of things. Nola might have a more specific recollection though.