Although not the best picture, you can see where the stamper letter is on the rim of the record.
In 1904 through the G&T company, the Victor Talking Machine Company would get a low cost brand of record called the Zon-O-Phone record. It was made from masters made in New York City and the records were stamped in Newark, New Jersey. These stampings were done at the Duranoid Company which was at 28 Prospect Street in Newark. The company would soon move to 213-221 Chestnut Street in Newark. By the way some of the original buildings are still there.
But this is where the stamping and production of all the Zon-O-Phone records would take place between late 1904 to early 1905 till around 1910. This company would also at times makes Victor Records, specially when there were some very big sellers.
The Victor Company had a set policy for their stampers and how they would be marked.
It was a alphabetical and numerical system. Let me explain
The first stamper from from the mother would be marked A . When that stamper wore out after making a 150 to 300 copies the next stamper would be used. This one would be called B. This went right through to Z. Then they would start all over again 1A, 1B, etc... It is not unusual to see some popular Victor records with 27 W next to the serial number of the record on the wax. This was a good system and it was quite understandable.
Then Zon-O-Phone was started and controlled from a distance by the Victor Company, there was a rather messy attempt to do the same for the cheaper label. However, I have been going through about 150 Zon-O-Phone records from 1904 to 1910. It is a very haphazard system. I saw that many of the earliest pressings from 1904 have no stamper info at all. Some others from 1904 have the stamper info right where it is on Victor records. But by what I can see by around 1905 is that all stamper info has been moved from the inside area by the serial number and moved to the outside rim of the record! This becomes a standard practice by 1905. I have seen markings that go from A to I and as of yet not any higher. But what I am wondering is, if this was the markings of the stampers, there were a lot of records that were not selling well.
If we can guess in the best conditions around 300 records could be pressed with a stamper, perhaps a little more. If the record shows a C stamper that means that there were about 1000 records made of that record. At least at the time of this records stamping. What I was looking for was the signs of a 12 W or anything like that. I did find a few crudely scratched numbers written on to the wax. I would see 6 and then a stamped C. The highest number I could find was an 8 B. This was found on only two records. That is all I could find on a 150 or so Zon-O-Phone records. So my guess is while they were stamped and produced by the Duranoid Company there was not a great deal of control or concern to mark the records by stampers in a very organized fashion. So I am guessing that many of the records that have a rim stamper mark of C, could easily have been preceeded by a 2 or 3. If not Zon-O-Phone was not making or selling many records.
In 1910 the company was brought down to Camden and all of the records were marked like Victor records. But the early years from 1904 to 1910 leave quite a few mysteries.