I'm trying to remove handes from a 25 yr old Harcraft tub set and of course the handles are corroded on the stems. I've removed the screw but I can't get the handles to come off. I have a handle-puller but even that won't budge them. I've gently applied heat - but no luck. I hate to destroy the handles but I need new seats/o-rings to stop the drips. Any suggestions??