I think the first job I ever properly quoted for (e.g. not a mate or an existing electrics customer) was to replace an 9100, it was fitted in a house that used to belong
to a BBC Bristol TV exec, who had got jumpy after the IRA had started targeting these sorts of people.
Needles to say they didn't bother as the new owners 'thought I could just get the old one going for £50', which may have been reasonable in intent if not price back in 1996.
Funny enough a couple of years back I did a job for a house once lived in by the former director of the IBA (later IBC I think), now rolled into OFCOM, who had been directly threatened
over the then IBAs attempt to block the 'Death on the Rock' docu made by Granada. They had also pinched the signs from the London IBA HQ and screwed them up in the loft,
still there IIRC as the new owner has zero interest in them. The (large) place was totally wired with door contacts and PIRs in every room - 2 live sirens, (long dissed) redcare, etc...