You tried asking around town to see if anyone has any linseed or similar that they can let you have some of, or sell you some? Or any of the WatCo Oil finishes, or similar.
I like the comment about flax seed oil. Vitamins by mail order! It IS linseed oil, takes about for frikken ever to completely dry though. Dunno what can be added to it as a 'drier', either, though some net searchin' could show that. Or of you can create you own 'boiled' out of it. But I do think Vitamin capsules would like as not make it onto the plane.
Best of luck in the dark, eh! Wassit they were saying? Winter is coming! Or it's already there, eh?
Cheers
Trev