Another option, if you have Linux/Cygwin/(probably)OSX, you can search through all of the extensionless files recovered by Photorec and use the `file` command to determine the type. Wallet files appear as "Berkeley DB (Btree, version 9, little-endian)", and so you should be able to find it relatively easily by running something like `file ** | grep "Berkeley DB"` (if you have globstar enabled, though there are many other ways of recursively searching every file within a specified location). You can use this technique for other file types as well, though anything plaintext will simply show up as "ASCII text" so it'll only help for binary file types with a specific identifier such as PNG (though presumably Photorec handles much of this, given the name).
Yeah actually that's a very good idea.
And you can simply do (without globstar)
find ./ -type f -exec file {} \; | grep "Berkeley DB"
(And replace ./ with the directory path)
Here's hoping 
