Apart from Dundee, all the airports involved used to be owned and operated by NATS and of those, with the exception of Inverness, NATS used to operate them with one controller providing combined ADC/APP service who was also airport manager, plus the ATC Tels Officer who was supposedly trained to operate as a FISO. Sometimes an ATCO Cadet (often 2 at a time in the case of Sumburgh) would also be attached for 4 week periods to help out although they weren't
supposed to work without the ATCO Manager being present.
Leave reliefs would be done by controllers from other Scottish airfields where NATS provided ATC such as Aberdeen and Glasgow.