Justanopinion, thanks for the comment - where should I send the cheque?
To say that the VC10 is no longer safe to carry passengers because it doesn't have exit floor lighting or GPWS is a bit like saying it isn't safe to carry passengers in a 20 year old car which has neither airbags nor rear seatbelts. It might not be as 'wrapped in cotton wool' safe as a modern aircraft, but it isn't 'unsafe'.
I don't know whether the CCWR has been upgraded from the orange porridge Ecko 190 the VC10 had when I flew them, but I would have far sooner had a modern radar system than a GPWS.
And yes, GPWS Mode 4A would possibly have stopped that C-130 wheels-up landing.
I don't know when that alleged 2-engine wheels-up approach was flown, but most of us had a 'personal' gear/flap/clearance check at '1000 ft'. But if it is true, then well spotted that ATC person!
When conducting instructor training, I would contrive to get the student instructor into a potential gear up situation, but only after secretly briefing the whole crew first. I would play the Bloggs pilot bit, querying the specific route of the visual circuit for long enough to reach the base turn, then call out 'flap - approach' and fly as normal - when the gear horn went off, the student FI was expected to take control and sort matters out. I expected him to go around onto the deadside, then we would discuss how easy it was to be lulled into such a situation. This ensured that the student FI would probably NEVER get into the same situation with a real student!
No, in the VC10, GPWS would be a 'nice to have', but I do not consider it essential given the presence of 2 well-trained rear crew on the flight deck.