There are quite a few Oil links between ABZ - OSL, I used the Brymon/BA service a few times when it ran but the Dash 8 was never more than half full when I was on it.
I note from the personnel involved with City Star that one of the named people is also (or was) heavily involved with a prominent travel company, this may help feed traffic to the route.
Good luck to them, I'll try them for my next hop to OSL if they're around.