The AVRO shed was dismantled end February/early March 2017. It had been sold over a year previously, only recently removed off-site. It is to be preserved by the new owner.
Peter Maher's complete LAC book referenced in Post No.5 above is viewable
here
The Helvellyn Mountain flight story is on page 2.
Centaurus - reference to dining in "a lovely old cottage type building on the aerodrome used as a Mess."
I assume you will be referring to the Avro and Lancashire Aero Club original clubhouse. In later years it was exclusively the preserve of Avro/HSA/BAe top management, who did not feel it was necessary to mix with the masses in the works' restaurants. Apart from the usual Royalty, VIPs and the like occasionally passing through, it also hosted a noteworthy 748 purchaser, Mr Howard Hughes, as this
video shows.