Thanks everybody for your swift responses.
LR, thanks to you and those who came afterwards, XX553 flies a treat and trims out nicely - no more "why bother flying at 3,000' when you might as well fly at 2,950'?!"
Beags, you'll be pleased to know that your trip to Marshalls was not in vain as XX553 still sports the '89 vintage VOR/DME/ILS mod which I have been putting to good use in the congested airways of SoCal. And yes, the distinctive smell of the cockpit is exactly as I remember it!
Coff, many thanks for the Twitter reference. I am also in touch with the ULAS ex-members association. I fear I will have to go through the archives pretty sharpish before THQ is sold and the inevitable clear-out begins.
Keep those stories and photos coming!
Many thanks,
ABL262