Other netlabels, like Kahvi, did mp3 for a while, then went to .ogg for a long time, then went to both .ogg and .mp3 after that. Of course, this isn't kahvi, but the point is that mp3 and ogg coexist well and you can have either or...
Also, I can definitely release in .flac if you want, but only for my newer stuff that I still have the source files for.
Maybe put a notice out to all the artists, that maybe they'd like to reencode their songs to .flac and you can put together your own batch torrent with select songs? Obviously not all are going to respond because they're either long gone or... dead but hey I'm interested.
Also: I kept suggesting .flac to zircon for the VotL distribution, but he didn't even put the .wav files in any archive compression whatsoever. Just to spite me... bastard.