I thought for your current RNS-D tuner you have purchased adaptor ("Kufatec interface") that allows for classical audio/video connectors. This adaptor looks approximately like this:
You will be able to reuse that adaptor with new RNS-E hybrid TV tuner.
BTW, when you do the upgrade to RNS-E and RNS-E TV Tuner you can reuse old cable, but not the connectors from both sides of the cable:
http://forum.a8parts.co.uk/showthread.php?t=2982