As to " where are the A-G (inc. I understand the close-up versions of Google Earth ) aircraft based ? " look around Blackbushe, not the gang who were operating C-172's, the other ones with twin engines...I seem to remember more like Islanders, though may be confusing them with other occasional flypasts by chaps in black suits.
If however they were A-G fitted Aztecs from a scruffy eastern town, start digging a bunker & run like hell if they re-appear, as the chances of them shedding a large part is quite likely !