My 1962 FJ40 block drain plug literally just fell off when I touched it with a wrench. Totally rusted through. The other portion of the plug is rusted into the block. Original engine. South American import ( I know what you're thinking). How to deal with this problem in the simplest way.? It appears that there was a small bit of fluid leaking from it fairly recently . Presently not leaking. Thank you for your help. I'm a newbie.