Honestly Beaggles, you are like one of those Japanese soldiers that kept on running around the jungle not wanting to acknowledge that the war was over.
After 21 years is this equipment so taboo that you think it's a figment of someone's imagination? The RDUs were fitted to some later HC2 chinooks - someone wrote that they had seen one in the right position on ZD576 the day before the fateful flight but perhaps he mistook the card holder as they would appear similar in a casual glance.
The early fits had the Control Display Unit (CDU) close to the main equipment – where would one sit/position oneself to be able to read the CDU so as to relay the reading to the pilots?
Could you see it from the jump seat or did you need to move your milk crate to near the rack?