Those taxi's were at ground level. The area is now the staff shop and an indoor walkway providing access towards T3 and the lifts to the multistory carpark.
So my question to you would be - how did the taxi's get in and out? The entrance / exit would be for cars only - as it is today?? What about the underground entrance/exit around the front of the car park? (if you're standing in the skywalk facing the terminal, look down to your left)
Also, in the top picture, you can see the taxi is about to set off the direction he is pointing. If you look at the tyre marks on the floor you can see where the flow of traffic is. Assuming this is an up ramp to level 2, this would be impossible due to that area being the terminal 1 arrivals lounge? If you stand in the current t1 arrivals lounge, there are no ramps, no supports, no pillars, nothing! No trace of anything?
Also, the old style travellators that went from levels 1, 3, 5, 7, 9 etc were presumably in place of the current lift shafts. I can't understand how level 7 would work, because at the time of the travellators, there was no skywalk system running through the middle of the car park finishing on level 7. If you stepped off the travellator on level 7 there would be no car park floor, nothing to step on, just thin air!