Well, congratulations to my talented, alert, Possum-focused readers who identified him out of a lineup of handsome Norwegian Forest Cats. Possum is #3, but even my husband thought he was also #7. (It could be that he thought that only I would keep and publish such an out-of-focus photo.)
To me, #1, #5, and #9 could have been his kitten photos, before his white ruff grew, and #6 (who is not available for adoption, unfortunately) could be an identical adult twin. The secret is to look closely at the shape of the tabby "bandito" mask around the eyes and the blaze of white on the forehead.
Here's a baby photo I found recently, taken before Possy's ruff and tail (and belly) developed to their full, fluffy extent. But as you can see from his expression, his personality is already all there. We're up in Maine, enjoying a rainy day, and I miss him and his sister.