but I gotta say I'm not really a fan of the 70s as far as folk goes. Most of my folk faves are 50s and 60s. I hate folk-rock though, so it's not surprising. But even the non-rock-influenced stuff in the 70s sounds a bit too 'brown tank-top' for me. Uncomfortably close to the stereotypes/jokes people make about folkies.
Oh, I'll also suggest this one too:
"Adam and the Beasts" by Alasdair Clayre, which is singer-songwriter psych folk at its most university don-ish and professorial.