[Vintagecatcher]

Thanks for the responses! I'm glad we could help update the big book!

As I suspected, I believe the Bardell Sepia San Francisco logo back is far and away the most common back. The next question is of the remaining 2 types of backs, ad backs or blank backs, which is the most difficult to find?

Here is a scan of the Bardell Sepia San Francisco logo back:




Thanks again for your responses.