Details of Silk-Spondon hubs.

Drum is a copy of the Fahron 2LS brake.

Drum is 8" where the brake shoes go in, the cast iron liner is 1-5/8th across the braking area, the liner is 8.5mm thick, 36 spoke holes, weight is 3.25kg, 11" overall dia casting, 2-1/2" wide ribbed hub, 3-3/8th across the casting including the bearing boss, 47mm dia bearing bore X 14mm deep. 

 
Disc hub is for twin or single disc,  155mm overall dia, 110mm across the disc mounting faces, about 87mm from bearing outer to bearing outer face, 36 spoke holes, 1.9kg in weight.
 

I have four drums one hard anodised grey all new but slightly marked and three disc hubs again new, bearings and spacers fitted, no discs.