Tips and tricks to get wiper motor outer housing off?

Picked up a wiper motor core.

67 Dart 2 speed???



It seems to be frozen. I'm trying to get the outer motor shell off.

I have tried light tapping around the shell where it mates to the gear box.

Tapping down where there is a lip I can tap on.

I put some light oil on the seam (can't find my penateating spray)

I have thought about a strap wrench to get it to twist a bit. The posts partrude so I can't turn it much.

I'm thinking about some localized heat.

Thoughts?

Successes?