I recently put in a bid on some decent looking 5x7 wooden holders on fleaBay. And I won!! Except they aren't regular 5x7 film holders. Now, to be honest to the seller, it is what was pictured. But they sure won't fit under a 5x7 spring back. There's no indexing ridge near the light trap, and the bottom of the holder does not fold open when I remove the dark slide. The only way I can see to get film in the septum is to curl it in up near the light trap with the dark slide removed. They are also about half an inch wider than a regular 5x7 holder, and longer, too. Frankly, they look great, and they're in fine shape. But what do they fit? Anyone got a clue?