IIRC, after Spidey got the symbiote off himself with Reed Richard's help, we saw it later break out of his FF base's glass cage somehow, then it's next appearance was Web of Spider-Man #1, right? Also, which Spider-Man title/issue-# was his escape from the FF building?
I know that it definitely happened during the De Falco/Frenz run. It was right around #258, maybe #260 or so. I THINK that it made an appearance in Spectacular before Web Of as well. I hope that helps. I think that you can get the Black Costume saga trade.