Thanks for the advice gents...here's the story so far......
Managed to beat the o/s brake drum off and discovered the lining from one of the brake shoes had come away and wedged itself between the other one and the inner lining of the drum. The brake cylinder was also damaged.
Have since replaced the shoes and drums and both sides, plus the damaged brake cylinder.
However, the drums were a pig of a job to get on!
Followed the workshop manual instructions on how to do it (setting the brake shoe adjuster to its' minimum setting) but the drums were extremely difficult to get on.
I knew it wasn't right, but I had to get the thing back together to just move the vehicle to a safer spot. Once the wheels were back on and the brakes bled (I drained the fluid to allow maximum free movement of the brake cylinder pistons to aid removal of th drums), the n/s wheel could just about be moved by hand when jacked up, but could not move the o/s wheel at all.
Any suggestions? I know it has to be something to do with the shoe adjuster, but unlike my 90 you can only adjust it when the drum is off - there is no adjustment nut on the rear of the hub.
I hope someone can shed some light on this!
Thanks