i maybe able to help as i aslo have one of these engines.
the first engine i built when i was 16 was a stuart 10v then i found out that there was a model engineer in the same village as me and i went to see him with the 10v in my hand, he told me he used to live right by stuart turner before he moved to shropshire.
james gave me a set of castings which he said stuart had made because the no1 was quie heavy and costly for some customers so they made a smaller size of it but it didnt really catch on and only afew sets were ever made.
i think my valve chest cover plate hasnt got a ‘s’ on it but i cant remember also mine had the base.
hope this is of help
jonathan
Edited By ronnie barker on 30/07/2011 11:34:33