Back in the mists of time BMA ran a late night IT from BHX to MAH, so they probably did others as well, and also the Viscounts were used for the pilgrims traveling to Lourdes, and the destination airport on the BHX departure board was Tarbes. At the time I believed the airports of Lourdes and Tarbes were different but having looked online it appears as though they are one in the same. Whether there were actually two airports back in the 70s, or if Lourdes didn't have an airport of it's own back then I don't know. I'm sure someone else will!
I'll do a bit of research into the BHX / MAH and see what I come up with, as I've got several of the old Birmingham Airport Timetables from that era that were published by an organisation called "The Airport Timetable Company" who I think were from Manchester. Did they pubvlish timetables for other airports? I would have assumed so, as they couldn't have made much from the 6d, then 3p monthly Birmingham one.