Hrm, here's a surprise- just announced on cpo, possibly what will be the only available recording, I believe?, of Stenhammar's quartets 3 to 6, played by the Oslo Quartet. See here (http://www.jpc.de/jpcng/cpo/detail/-/art/Wilhelm-Stenhammar-1871-1927-Streichquartette-Nr-3-6/hnum/9983874).
(My high estimation of these works - especially nos. 3 to 4, which I have in several recordings, mostly broadcast but also that of what was once called the Gotland- now Zetterqvist- Quartet- on Musica Sveciae - I think I've mentioned.)
I've the 6 on Caprice by different ensambles. Lovely romantic works.
Exciting news indeed. These are among the finest quartets written between Brahms and Bartok.