TxGoat wrote:
That doesn't look too bad in the pictures. Original grease, some surface rust, but pretty solid including areas under the running boards that are often badly rotted. I'd drive it. A member posted some pictures of a seriously rusted frame and under body a few weeks back. Look those pics up and compare. Your car looks well above average for a 1941 model that's never been cleaned up or painted over. The bolts on the inner fender may surprise you, or they may be hopelessly stuck, I'd apply penetrant and then try removing them the next day. A little heat may help. My '37 has a number of small bolts at the top of the panel, maybe 6, and 2 down lower. The panel is made to be easily removable to service the engine.

Your engine may have stuck valves or some rust in one or more cylinders. It takes VERY little rust to jam an engine.
Taking the valve covers off and spraying the stems may help.
I'd add some more oil to the cylinders and leave the plugs out, then rock it back and forth with the ratchet from one tight place back to the other. That will usually allow more and more movement until the engine can turn freely. Leaving the plugs out will relive any compression and will also keep the engine from hydro locking if too much oil is in one or more cylinders.