Nice phones, but well over 20 years old now and genuinely rare "in the wild". I think a single phone and base cost nearly £200 when they came out so I can see why you're reluctant to discard. They had a set at the first practice I worked at in 1998, and I was blown away by how well they worked compared with the Uniden/Tandy/BT Freeway analogue rubbish I was used to.
I've got the manuals for the 1010 and 2000. Any use?
Note that one of the 1xxx series phones was DECT
but not GAP so you couldn't link it to other systems.
Nick.
P.S. I think you've got some interchanged digits in your model numbers somewhere