thanks Dave
I was going by the list on the double gunshop board to determine model- that shows Crass numbers up in the beginning of the 94K range, with the Lewis model starting with 94109.
http://www.doublegunshop.com/dgsnos3.htm
In spite of growing up near there, I never paid much attention to their doubles although there were a lot of them around when i was young.
But the condition of this one caught my eye- if it has not been redone, it has withstood the years well.
you say "screw from the outside of the forearm wood into the forearm metal like many later Ithacas have" so is that a feature on the Lewis