Cameron
The "Como" cone-shaped spark arrestors first turn up between 1911 and 1912. The familiar Ridgway stack showed up in the late 19teens. So the good news is, if you model in the year 1907, you don't have to make any!!
I made a couple in HOn3 many years ago by taking fine brass screen and forming it over a bluntly sharpened pencil. A ring of brass strap, slightly larger in diameter than the straight stack, was forced down onto the screen and soldered into place. Brass strap was formed for the two mounting straps and attached to brass wire pins on the stack (drilled through the stack and inserted a single piece of 0.015 wire and soldered it in place). It looked good and moved on the pins, but is the kind of tedious work one best does in his 20s or early 30s, not in ones 60s.
It's great to know that there is another first decade C&S modeler on the site. What scale do you work in? What part of the C&S do you intend to model?
Jim in the NW
Jim Courtney
Poulsbo, WA