I could be wrong here but I suspect that 06/24 grass was closed when the hard taxiway was built to the new hangar near the old LFC and Helitech hangars. The taxiway was partially constructed and then left moribund for some time, as I suspect you probably recall. Some of the wags in ATC used to refer to it as 'The Raisbeck memorial parkway'.
This has got the brain matter working overtime. You must mean this hangar that was for The London Aviation Centre but apart from the hangar and the offices either side nothing else got finished. Even this hangar is gone now.
from the David Gearing collection via
Luton Anorak
I can't remember the taxiway being built but then I seem to remember it had to be made wider for the cargo apron that followed years later, so it must have already have been there.