What I understand this isn´t sold as enclosure, but CD with some other stuff was sold at Comic Market 87
http://www.suruga-ya.jp/kaitori_detail/185134458
Catalogue number from here:
http://www.suruga-ya.jp/product/detail/120090721001
Now is CD available at Bushiroad e-shop. (link in album page)
I almost bought complete edition DVD but don´t find any clues about inclusion of soundtrack CD