The vinyl of Nobunaga's Ambition: Sengoku Gunyuuden is on YJA right now:
http://page8.auctions.yahoo.co.jp/jp/auction/h136780674
The photos are attached to this post.
The catalog number is clearly visible KCS-001. Unfortunately, there is no information about the release date.
If the information regarding
http://vgmdb.net/album/11252 is correct, it could very well be April 20, 1989.
KCS-002 is
http://vgmdb.net/album/924 by the way, but again no release date.
It also seems strange to me that these vinyls were supposedly included with the games.