I don't know where to buy small amount of kerosine, but maybe You should ask it from Shell Aviation at Turku Airport.
Shell Aviation, (02) 415 4960, mobile 040-5684960, fax (02) 415 4762
Mon-Fri 06.00 - 21.00 hrs LMT Sat 06.00 - 18.00 hrs Sun 08.00 - 21.00 hrs
Avgas 100LL from card-op pump24H/Euroshell-card, Jet A-1 servicehttp://www.finavia.fi/airports/airport_turku?pg=1091739
Actually there is an old topic about kerosine. It's a finnish but let's try some Google translate: Kerosine topic
You can buy kerosine trom Turku Airport on Your own barrel.
I don't know Paimio so well, but I know that there is a lot of fields that could be used if You get permit from owner.
We have great flying fields at Masku