Wow, made more progress than me. I fancied making the Blackgates Crampton but after three attempts to contact them to ask about drawings and copies of articles etc, had no reply.
They are in the EIM from a long time ago, I have a few of the articles but since so little support is available I am just sitting on my hands at the moment. I would be able to say what year the articles were, but EIM didn't bother to put the date or issue number on the pages, amazing. Mind you, some MEs didn't have the date or issue number on the contents page, amazing squared.
Certainly an interesting looking loco, make a good gate guard.