405 front drum brake advice

[GlennBurnage]

Hi all, I'm new to this forum and I'm seeking help. I have a Werner Oswald Frazer Nash Le Mans replica copy and it has front drum brakes from a Bristol 405. These are Lockheed TLS 12". The car is new to me and the brakes were binding unacceptably. I stripped them down and addressed all the 'gunge', corrosion, cleaned and fitted new seals to the slave cylinders. Upon reassembly I find that they are still binding unacceptably with the drums up to 40-50 degees C after only a mile of running. The w/shop manual says to apply the brake pedal and the shoes should adjust themselves automatically and to check that the drums are 'comaratively free' when the pedal is released. The ratchet system, as far as I can tell, seems to be designed to keep the shoes in contact with the drums when the pressure is off!!! There seems to be not way they can back off enough to enble bind-free rotation of the drums. The springs also seem to be placed so as not to be able to pull the shoes off the drum as effectively as they could be, that is, they are placed near the fulcrum end, not near to the actuating/slave cylinder end.
Can anyone shed some light on how this set-up might enable bind-free rotation as I'm worried about warping the drums??