DND/MAN was indeed operated by (the much missed) Business Air until about 1997 in their own livery and then continued to be operated by British Midland Commuter for a little while before they scrapped it. Business Air's pax figures weren't fantastic but never extremely poor either. Business Air used to operate INV/DND/MAN and back in the morning and then two separate flights in the evening - one going INV/ABZ/MAN and the other ABZ/DND/MAN. The average DND/MAN sector would attract about 12-15 pax I'd say but that was with only two sectors in each direction each weekday. I think Eastern will have to be a bit more reasonable with their prices on the DND/MAN route than with their other routes to be able to attract an 18 seater plane full of passengers three times a day. I'd advise them to advertise the route very well locally - a failing of Business Air's that I'm sure didn't do the route any favours. A lot of people in Dundee were unaware that there was a DND/MAN route when Business Air operated it.
Good luck to Eastern. Nice to see DND getting on a bit better too. All DND needs now is a carrier willing to operate to LTN and offer industry employees a hefty discount!!!