4ft HSWT Exhaust, 1968 (could be 1969)
personnel from the 4ft (Mach 4) and 18in (Mach 6) blowdown tunnels

Back row L-R:
John Tizard (?) (4'), Mike Walton (18), unknown (4'), unknown (4')

Front Row L-R:
John Parker (18"), Tony Archdale (18"), unknown (4')

photo from Tony Archdale, March 2015

can anyone supply the missing names?