LV
I was a very young Sgt on MAMS at that time having just moved across from Abingdon. I remember the period as I had to do my month's stint as Sgts Mess Barman 30 Apr - 30 May but don't recollect Concorde landing. It may have been a 'touch and go' as I also know that you need the 'hi-rise' steps to gain access and at that time all we had were mediums for access to VC10/707s.
Also had the privelege of an 8 hour ride in G-BOAC in August the following year when it came out to Singapore on hot weather trials. Paya Lebur-Kuala Lumpur-Bahrain-Bombay-Paya Lebar in a day with lunch in the Gulf, what a trip.
The Concorde still hadn't gone commercial in 1974 so it may be worth speaking to the Bae people at Filton or even starting with the Bristol Aviation museum at Kemble as some of the Filton 'Old Boys' still frequent the place. Good Luck.