Ta for that Kreuger - my bad, as my son tells me they say on t'internet these days.
I should've checked, of course. I keep a framed 1:100,000 map of the area from the "new" (well, it was in 1982) survey as it's such a beautiful example of the cartographer's art. Sure 'nuff, the runway at Saiq is labelled as 6508' - I was using the figure we derived from the old photo-survey-based charts which only had spot-heights in odd places.