BOAC:
Incidentally, I see that 8260.19E at 2.74 calls for 200' to be added as an AAO which may account for the 200' discrepancy we see between the FAA and Jepp chart 'spot heights' (basically to allow for the 199' mast), and 2750' + 1000' gives us the 3800' hold, I guess.
Chart makers don't use AAO for reference obstacles.
But, the designers made additives to the holding pattern's minimum ROC of 1,000, probably for precipitous terrain and, more important at this location, cold station altimeter errors.