Aerostar
I went to ESOW. Details are on the excellent free LFV
site .
I recall that I phoned the airport number given there and they referred me on to the flying club who supply the fuel (Cash as I recall it). I taxied directly there and didn't go into the terminal at all. They found a hotel for me. The cab ride into Vasteras was only 2-3 miles max. The hotel was 5 min walk from the station and you can buy tickets on the train but it costs more than buying them in the station (but still very moderate).
David