FELIWAY! Yes, it is the pheromone spray.
It can be expensive - but one bottle lasts a LOOOONG time!
Ask your vet if he has a trial sample you can use. You do 2 - 3 sprays a day, or whatever the vet says (on kitty's favourite spots).
My Oscar is on it for life - even though he was wild, and has been a total suck for two years without biting or anything, he gets just stressed enough that he will get UTI's and other things. Your cat's early trauma has no doubt affected him.
Please try the Feliway!
AND - there have been great reports here on an animal psychic - I think Moosmom has the contact.
"When I think of Mick Jagger still singing that he can't get any satisfaction in over forty years of being in the Rolling Stones, I have to conclude that he's either lying or not all that bright." -- Henry Rollins