I posted this at PT also. I was restoring the Parker Challenger this evening (new sac and pressure bar / cleaning etc) and it reminded me of a CS 55 I have. I put them next to each other and the similarity of the pattern was amazing.
The Challenger was made in Wisconsin USA in the mid 30s and the CS 55 was made in the 40s in England. The picture doesn't fully capture the similarity of the green and white pattern, but it is very close.

Have a good evening