Links to separate pages for each of the old versions, with tech specs as best we can do for each of the old releases. We are solid on 1.7.0 and 1.4.5 as well as whatever version the LR manual was last updated, so interpolate from these.
Possibly only allow public downloading of 1.7.0 and 1.4.5 and only allow other old versions if logged in?
Create pages for each of the version releases as child pages to Downloads, rather than child pages of this page, so the URL is prettier ( /downloads/liquid-music-1.7.0 instead of /downloads/repository/liquid-music-1.7.0 )
The links should probably be part of the header or footer or floating or something