Can I download firmware for devices released before 2013?
Sony Mobile deleted older devices when they migrated to their new API.
Moreover, they keep deleting old devices from time to time. There's nothing I can do about it.
Can I download older firmware? / Why there's only one firmware version in the list, while there were multiple before?
I have no control over which firmware show per CDA.
Sony Mobile deletes older firmware, and there is no way to download them after that.
Try finding your FTF on http://www.xperiablog.net/forum/resources/.