Thank you for your advice, it worked.
I pasted the very long URL into the browser navigation bar
and it sent me to the front page of the HighSlide editor
When I clicked on 'get started', it opened the image manager
at the sought-after previous collection. So far so good.
When I requested a reedit for a slideshow that was created
in December, I got some generic images. So I guess about
one month is the time-frame for holding onto your stuff.
Its OK though, because you can still edit the source-code and
the '.css' file in DreamWeaver and update both the pictures
and the comment overlays and change them all you want.
P.S. No wonder I couldn't find the path to load a previous
effort. Its not obvious at all. Would you consider including
a 'load file' command in the editor