i once did a absolutely knackered copy of will collins on bareback (been left out in the sun)and i mean knackered in fact wrinkled I held it over a electric hob on the oven watched it sart to soften ten laid on the work top and i swear to you i watched it straighten out result was a plays perfect copy its still rough but well worth keeping just a one off ive done and I think I was lucky I must have timed it to perfection pure luck as some vinyls will react differently to others I would imagine ,but there was a thread on here some time ago with loads of different methods
atb
dave