I am going to start restoring a Westinghouse double arm electro-pneumatic shunting signal. Actually there is little apart from the main post casting but many parts are identical to those of the single arm variety of which I have a couple so can be copied. One part that I can not find enough details of is the post cap/finial. Does anyone have a picture of one of these (or indeed a spare one!)? I'm not sure how widely these signals were used, I can only recall seeing one at Bolton West but I'm sure they more widely used. The single armed variety could be seen at Southport and Salisbury in relatively recent times.