Had another close look at the rears today and they are binding only in certain places...making me think its the drum that's shoddy! Is it worth getting someone to machine it good? Some of the quality of mini parts is really starting to p*ss me off!

Drums get misshaped by people tapping with a hammer etc when the buggers won't come off.
It might cost more to get them machined on a brake drum lathe at a brake shop, than you can buy new ones for. You cannot hold them properly in a lathe chuck on a normal lathe as the jaws distort them out of round. (I'm a machinist and yes I have tried).
Also if you machine them out bigger than stock 7" the brake shoes won't match the drum radius and will take a while to bed in.

They are under $85/pr at Karcraft for new ones, made in Italy.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.