My observations are only to make sure the kind of fork you want matches your frame. There is a big difference between the fork on my Claude Butler with 2 3/4" of rake and your 1 13/16". When I was learning how to build frames at Ellis Briggs in Shipley West Yorkshire in 1975, I don't remember any fork specification measured to a 16th. That does't mean Cluade didn't do it - especially if their own information says so . Philfo already mentioned the need for an axle to drown measurement that could be different between models and their intended tire sizes.

I was surprised the Claude Butler in my shop is a low trail model. I thought only the French did that back then. Your rake would be standard for a high trail bike. My seriel # is 9125962. On the other side of the fork steerer (opposite the serial #) is stamped 30226 (whatever that number means). Here is a quick pic. I can do a closer up one if desired.


A bilaminate Claude Butler frame with a fork that has 2 3/4" of rake and a 74º head angle