I found both my 1.02 and 1.10rc23 ISOs, burned them to a special lot of 650MB CD-Rs I'd acquired years ago for a project then spent a lot of yesterday doing upgrade testing.

Will post results of that test series in a new thread.

Now need to see if I can find my copy of the 1.04beta Rio Receiver software.

ETA:

If anyone needs these and comes across this post in the future: I don't have a Dropbox account (yet) but will create one if necessary.