Silverwork and Pewter
( ( Silverwork and ) Pewter )
(ROOT (NP (NN Silverwork) (CC and) (NN Pewter)))
Petwer and Silverwork are not comparable.
( ( ( Petwer and ) Silverwork ) ( ( ( are not ) comparable ) . ) )
(ROOT (S (NP (NNP Petwer) (CC and) (NNP Silverwork)) (VP (VBP are) (RB not) (ADJP (JJ comparable))) (. .)))