A few more that spring to mind....
As usefull as a one legged man in an arse kicking contest.
As thick as shit in the neck of a bottle.
As bright as two O'clock in the morning.
A face like a hen laying razors.
A face like a skittery hippen ( soiled nappy/daiper)
A face like a wet night looking for a dry mornin'
A face like a bag o bruised fruit.