This has been brought up many times before (Until SG Classic came out). I personally think that all these maps would be great for SG Classic. I think people dislike SG Classic a lot is because of the bugs, how there's only two maps, and how long the games take. I think that SG Classic should be your idea, sort of making it in the later part of MCSGv1, like in December 2012 and January 2013. Old Solar Frost will never be re-added, because there is no file for it and some other reasons, unfortunately. Otherwise, yes, I think all of the MCSGv1 maps should be added to SG Classic and the time should be shortened to 30 or 40 minutes per game to attract more players to SG Classic. These maps are: Survival Games 1-5, Skyland's Survival, Yellowstone, Old Solar Frost (Which again can't happen), Teweran Survival Games 1 and 2, Insanity Cause, Survival Games Ancient Japan, Hungry Hills, Overgrown Arena, Breeze Island, MCSG Ruins, Kharmunrah, and Survival Kingdom.
EDIT: I said SG Classic a lot in that paragraph l3l