Manchester Helicopter Charter Company used G-BPAI primarily for pleasure flying from their base at Manchester Barton around that time.
That's a good, if inadvertent, illustration of how difficult tracking down the Bell 47 in question is likely to be.
While G-BPAI may well have been operated by MHCC, they were never the registered owner of the aircraft, which had two owners while on the UK register: London-based Bola Ltd (1988 to 1993) and Huddersfield-based LRC (Leisure) Ltd, before being cancelled from the G- register in 2007 (although it still operates in the UK on a US registration).