[sb1]

Here is a scan of the back of an overprint, I can email it if needed.

As to your questions.

No other company has been confirmed to be a part of the E107 distribution, but it appears very plausible that it was used over a period of time by different parties, given the different backs and the overprint.

I believe that the overprints are all one of ones and unique to only one of each player overprinted, I have not seen a double of any player. My original "set" had 39 overprints a very, very high number when compared with most large holdings.

The overprints were probably done after the fact, not prior to be inserted with a product or given away. As you may know I have a Type 2 card, which is highly likely to have been part of candy packaging, that has the backstamp as well. All of the stamps are uniform and slightly diagonal(the stamp is too large to fit perfectly centered), almost if they were done at the same time. I had a few that had purple ink on the front from being stacked atop a freshly stamped card. ALL of the stamped backs are on 150 Subject card, I have not seen one on a blank back, other the Type 2.

The ones you still lack scans of are the very hardest of the team variations, a few of which are limited to 1-2 examples known.

One last tidbit that will give you some more to research, is the fact that many of the blank back vs. 150 subjects backs have different font widths on the front player name and team resulting in wide vs. narrow captions at the bottom.