Arabian Nights Sinbad no Bōken / アラビアンナイト シンドバットの冒険:
Only the German (European) version of OST was released. If you watched that anime in Europe during the 80s or 90s, chances are you are looking for this album:
http://vgmdb.net/album/25066
Kaiketsu Zorro / 快傑ゾロ:
Unfortunately not and it is really a shame, because the BGM from Hiromoto Tobisawa is amazing! The only album related to Zorro (TV Anime) that was released was this one
http://vgmdb.net/album/27229 which features an acoustic version of the main theme.
Unfortunately there are other great soundtracks that were never released. Those anime are:
- Jungle Book: Shounen Mowgli
- Fantasy Adventure: Nagagutsu wo Haita Neko no Bouken
- Huckleberry Finn Monogatari
I'm pretty sure there are more out there, but these are very memorable.