In Exlorer I only see the version of the Find DLL in my solution, not the version on the Find server I'm accessing.
If you use statistics tracking, you can view webpage source, and you will find some find related js reference. I am not sure that's the version you are after.
I do not think it is. I checked two sites that should have different versions on the server, both showed:
Given the URL to the index, is it possible to check what version of Find it is running?
I've got an "on premise" installation without remote access, and are curious about what version it is running...