Anyone's 904 Torqueflite Not Leaking or Dripping ATF?

After turning around the '65 Formula S in the driveway for the first time since drivetrain has been re-installed after body restoration, it stopped moving both forward and reverse (just stuck in place). Seems like the park sprag won't release.

Going to look at the cable that controls that later today. I can feel the transmission lurch a little changing gears from reverse to drive and back again, but it feels like the brakes are set.