steering lock removal

I've tried without success to remove the steering locks from 2 spare handlebars I've had sat on the shelf for 30 years. I have the keys for the 2 locks. I've removed the grub screws which I thought were the only things securing the locks. Neither handlebar has any paint restricting movement. I've heated the handlebars with a bunsen burner and repeatedly applied 'Plus Gas'. But the locks will not budge. Have I missed something? / Any suggestions gratefully received. Cheers