Hello,
I think it all boils down to the unsavory subject of who owns what. It seems that Cass' solo stuff is owned by many different corporate entities and they're not always conducive to harmonious negotiations. Recently, Owen shared here that a possible DVD release of Cass' solo appearences wasn't feasible, since the rights to license them would be astronomical and cost-prohibitive. It would be awesome if Owen owned all the rights to Cass' stuff; then we could have a thorough re-assesment of Cass' audio and video legacy done with love and attention to detail. sigh... If only life were that accommodating!
In the meantime, here's hoping for more gems, undiscovered or not! Maybe the reissue of "Please Don't Call Me Mama Anymore" with the alternate studio tracks that was hinted at on this forum recently?
Peace to all.