i think my rear left drum on my '74 120y coupe is completely stuck and the right one is just slightly sticking. ive got the back end up on blocks at the moment and only the right wheel spins, with no movement in the left.
anyone know how to un-stick them??

Unadjust the adjuster all the way (anticlockwise). You may need to use vise grips if the adjuster is rounded. I think maybe the shank is3/8 ???? ,any way undo them and if the drum wont come free try shocking it with a hammer. If the adjuster shank (square) gets too rounded thet are a c*** to get off.

cheers, i'll try that tomorrow after work

The adjusters are 1/4 inch square.

sasquatch_nz, after you loosen them, just drive the car. If the back wheels turn, you have freed them up. If necessary, you can "shock" the brake shoes loose from the drums by revving up and dumping the clutch. After, this remove the drums and inspect the brake linings.

If the drum are rusted around the hub (very common) you can use a welder's torch to heat up the drum around the hub until it "pops" loose.

An easier way to remove the drum from the axle is to use the threaded holes in the drum and fit 12mm bolts in the hole. Turn the bolts till the drum comes of the hub. Once you have some tension on the bolts the hub comes of easy with a tap normally even on the most stubborn drums.
Stuck/rusted shoes normally come loose when doing it this way as well.