I've missed this one totally!
Yes, Raitio. I had a Raitio phase couple of years ago after I read an interesting article about him in the Suomen Musiikin historia 3 (History Of Finnish Music) by Erkki Salmenhaara. I agree everything you wrote about his music being part impressionistic and part expressionistic, little scriabinisque and very chromatic, basicly free-tonal. (I hope I don't mix terms here, maybe it's actually post-tonal) Of course his music wasn't that right from the beginning and there is quite an extensive body of works (a symphony, a piano concerto,a string quartet, and a violin sonata among other things) in the rachmaninovian late romantic vein.
Since I'm a Finn, I have easier access to his works than foreigners. The problem is that many of his scores aren't published and not even recorded. Did you know he composed operas? In the 1930's he devoted much of his time creating operas. In the sibelius Academy I have seen many of his scores which are copies of his original manuscripts. I'm pretty sure that Kuutamo Jupiterissa (Moonlight in Jupiter) has been published but there's no commercial recording of it, only a radio tape which again is available for listening only in Sibelius-Academy.
There are only few recordings I can recommend;
-Orchestral Works: Antigone, Fantasia poetica, The Swans etc. (most of his main orchestral works) ONDINE
-The String Quartet in g-minor (Savonlinna Quartett) MILS 0075
There appeared few years ago also a sheet music of his piano works. Charming pieces!