Steve;

This is a well-known issue with 544, 122, and 1800 vehicles, which has to be addressed every time rear Drum Brakes need servicing...but STOP!! before proceeding ANY further!

"beating on the drums with a small sledge around the the circumference" is a sure way to break the Drums, even before removing them!

To remove Drum you must break the stretched-on tapered joint connection between Drumhub and Axle. This should ONLY be done using a proper Puller of the accepted type, and correct techniques, because high forces (at least!) need to be applied...sometimes, ultrahigh forces are necessary, and these will be enough to, if applied wrongly, damage, bend, or break things.

I have captured everything you need to know...suggested reading BEFORE proceeding ANY further: https://www.sw-em.com/Brake_Drum_Notes.htm

Good Hunting!