The Amazing Spider-Man Annual #13 (1979)
“The Arms of Doctor Octopus”
Writer: Marv Wolfman
Artist: John Byrne
Some agent gets murdered. Cops think it’s suicide. Spider-Man investigates to prove it’s a homicide. Dr. Octopus is also looking for the murderer, but for different reasons. The guy helping Spider-Man (who also knows that he’s also Peter Parker) turns out to be the ghost of the agent who was murdered. And during a fight with Doc Ock, Spider-Man rips one of his mechanical arms off.