Thanks very much Brian, that will be great to read through. I'll let you know how I make out.
OK, on the RemoteLinc2, I finally got it licked... My improvised plan from all your ideas was to take my new Insteon On/Off 2635-222, link it to my ISY, show links, manually link it to the RemoteLink with the unknown address, compare the two link tables and voila, the new link should be the link for the remotelinc2. Almost... The new 2635 had 5 links out of the box, and none that were showing up were making sense. So, what I did was to manually link the 2635 to 4 different buttons of the RemoteLinc2. Then there was no doubt, the four repeated addressess were the remote and the one hex digit was the button number. This worked. The addressess in the links table are not self evident. There's a 4 byte address which I still am unsure of, then the addressess in the device links table has a 2 byte address like AA , A2, or E2. Not sure what that part is. Then the next 2byte address is the button id followed by the 6 byte device id. In my case the mystery remotelinc 2 ended up being 1c.43.33.
Thanks to Brian H. and Teken for all your advice and attempts to get me on track. It's really odd that there's such reliance on such a ephemeral item like an address label. Being so imporant to making the Insteon devices work it would be good if they'd make the labels a bit more indelible.
I'm sure I'll be back soon to chat and seek some more advice... Thanks much. . Chris