Oh and the absence of the RDU isn't conclusive - a quick fit (30 minutes) would not involve the RDU - the CDU can be left plonked on/near the ARS6 module and the readings relayed to the pilots by a loadmaster (which may explain why he was not at the window seat doing his "sideways" navigation).
For a feel of the size of the ARS6, compare the following piccie of the complete equipment with the above cockpit (recognising the RDU):
