I'm fairly certain that I can remember looking at an Air Anglia timetable in the 1970s which had Humberside (to London?) flights split between Brough and Kirmington.
On the theme of Brough, am I right in thinking that Holme-upon-Spalding Moor had some connection with the factory? Does the airfield still exist?
I believe Air Anglia used Leconfield before Humberside Airport opened, as did Humber Airways after Brough lost its licence.
As for Holme on Spalding Moor, just to add to what Chevron has already posted. HoSM was closed in December 1983, the runways were quickly removed, I believe to use for hardcore in various local road schemes in the late 80's. All that is left of the main runway is a narrow farm track along the full length of the former runway. I believe the tower was also pulled down soon after closure. The rest of the site survives in good condition (including two T2 hangers, now joined together, and one J-type) and is now an industrial estate.
I believe Brough was home to a PC-9 for a number of years, however not sure when it was moved to Warton? The Jetstream corporate shuttle flights ended sometime in 1992, and the radar was transfered to Humberside Airport in 1994 I believe. With the exception of the families days until the mid 90's, the airfield hadn't really been used until the recent decision to fly Hawks out on delivery flights, but these have now ended too.