2 ways to go here:
As already pointed out, you could use an MCL 'starter' cable connected to the 'speaker 2' output on the 4500, and splice that to a special 'MCL' cable meant just for the 3500.
Alternatively, you could purchase a BeoLink Converter, connect that to the Tape 2/Aux socket on the 4500 and then run the newer ML network cable tl the 3500. This option would allow you to prepare fore newer B&O gear in the future, like the BeoVision 7.
Russ
We kid because we love.
Bang & Olufsen Tysons Galleria
McLean, VA USA