Oh dear me TTH, I hope you didn't put any money on my knowing the first guided weapon fired in anger by the RAF - not really my bag so to speak.
We can exclude Fireflash on the Swift! I have also discounted the rumour that a Firestreak was fired from a Javelin in the Malacca Straits, leading to the demise of an Indonesian Hercules. PGMs don't count - different set of rules really.
I'll go for a Shrike fitted to a Vulcan and fired against the Argies.
Old Duffer