This is a top-down seamless vest in a simple stitch pattern. For size S, only 110 g of the yarn is needed! For size L you need 150 g. Another Estonian yarn, Aade Lõng 8/2 would be a good substitute.
The pattern is available from Käsitöö 2010/3 in Estonian and Käsityö 2010/3 in Finnish.
The upper photo by Mark Raidpere.