Hi, Fly fisher, Are the rear brakes locked on or is the handbrake fully on! ie. is the handbrake fully working or has the mechanism had a disconnection yet the ratchet quadrant is still engaged.
So first check is does the handbrake mechanism release the cable tension. check this at the rear hoop top edge where the H/brake adjuster is.
If the cable is slack at the adjuster then rear wheels off and if both are not rotatable a nylon hammer to the drums may free off stuck shoes. If that doesn't work then remove the oval rubber bungs on the rear back plates and using a screwdriver pull the self adjusters down to release shoe pressure on the drums... GoMog will show you how.
The hand brake actuator is directly below the handbrake in the transmission tunnel and the cable runs down the length of this too, you don't describe the failure to function problem so it's difficult to assess what is happening there ie. what is the handbrake actually doing. last question is has the car been parked after being out in the wet or for any length of time with the handbrake left on?
Just as an aside, if an handbrake cable quadrant has worn and won't engage in the on position new quadrants are available. Yo can sometimes re file the teeth to improve the function but its better to buy new as access often requires a bit of work!
