Removing the body is like moving a house - you will need to support it well under all the body mounts or you risk tearing it apart at the cowl and windshield pillar attachment points at the roof.
There are a lot of joints in the wood that were glued and often the glue is long failed and the joints are held together with a single bolt that allows quite a bit of rotation / flex.
Take it slow and easy - and if that motor doesn't free up - I have it's replacement sitting right here ready to go!
