Until now, this release was thought to have been a mail-in bonus with the purchase of a 16,000 yen art book released in 1988. However, the art book in question, which contains concept illustrations for the DAICON openings, was listed in General Products' 1984 catalogue for much less money. (The VHS and Beta releases were listed separately in that very catalogue.) Additionally, General products ran multiple advertisements in 1988 that listed this LD, for 16000 yen, without any reference to an art book.
The disc label and jacket says mono soundtrack, but it's unmistakably stereo, especially for Orochi Strikes Again.
Interestingly enough the order of the features are: