WEBF
Think how much effort was needed to get the Gannet back into service for the Falklands. They had to use the apprentices at Yeovilton, supervised by the museum staff. They only got it flying AFTER the ceasefire and were still trying to get the radar working (as in raiding museums for parts)
As it was they were lucky in finding a privately owned cache of unused crated Mambas (they had been intended for conversion to emergency power stations during the miners strike - but never got used) otherwise the Gannet would never have got it in the air. There were NO spares for the Mambas otherwise
A similar situation will apply to the Sea Harrier - you are not going to find an unused cache of Pegasus anywhere