Thanks for this, which confused me. However, the penny has now dropped. The reference I have to flights by 134 in December 1992 are not, in fact, ZA134 as I thought but refer to the callsign rather than the serial. Thus, I’m looking at Rescue 134, a Wessex from B Flight, 22 Sqn at Leuchars.

Thanks nonetheless for your help and sorry for any confusion I’ve caused.