"Is the motor free now?"
Guess we'll never know. One post then ... gone. A drive-by poster.
Spent the last two days "freeing" an 8BA that truly sat in a barn for 25 years. This thread kept coming back to me.
About the "rocking the car" technique. The younger guys tried that before older, cooler heads arrived. The pistons freed up but they popped two valve guide clips off(!) and shoved the valves open with the one-piece guides firmed attached ... three valves were so stuck that only removal and careful heating loosened them. Half of the rest of the valves were so stuck that no long term soaking would have cleared them.
Point is, if you spray some stuff in the spark plug hole and dump a little something or other in there ... and the engine frees up, the engine was just "stuck a little." It was not "stuck."
I hope that anyone tackling a seized flathead will go gently and as some others cautioned ... make sure the valves are free. If you are unwilling to at least remove the intake, maybe you shouldn't be messing with it. With the cost of machine work and the difficulty in finding good flathead shops, try not to damage more than you "fix."