Sorted out the artists.
牛鰈 = ushikarei (source:
http://8617.teacup.com/ushikarei/bbs)
It's not explicitly written, but 牛 = ushi, 鰈 = karei, ushikarei is in the URL and the bbs page has something to do with Circle S&G, so it matches up.
槇タケポン = Takepon Maki (already in database)
羽鳥風画 = Fuga Hatori (source:
http://wamojsbhhtr.sakura.ne.jp/blog/guidance/)
And track 2 is from ONE ~Kagayaku Kisetsu he~, originally composed by がんま/Ganma (an alias of Shinji Orito).
By the way, where did you get Amstrad and NEC PC-98 from? All the games seem to be for PC.