Hello Lovat, et al.
I share your quest! I also have one of these badges and enclose pics as it appears not to have been polished or shows a different finish. Same maker tag on the back, though not appearing very clearly in my pic.
A peek into the Library and Archives Canada digitised records of the CEF shows No 32 Company of the Canadian Forestry Corps operating in La Foret de Dreux, France.
http://data2.collectionscanada.ca/e/e060/e001480534.jpg
The IWM provides a 17 minute film clip of the SA Forestry work in France in 1917. (A variation in the text description drops the word "Native" from the nomenclature of the unit - last line). The clip is fascinating
http://www.europeana.eu/portal/recor...2/IWM_413.html
Text: "The film opens with Number 1 Camp of the contingent by a wood, and a posed group of the black NCOs with their white officers. The NCOs are all "native chiefs". Members of the contingent unload boxes of supplies at a dump from railway wagons, while others use picks and shovels to dig road mending material. The main part of the film concerns the contingent at work in a forest cutting down trees and transporting the logs by means of light rail sledges drawn by horses. The logs are cut to a manageable size by a belt-driven rotary saw. At lunchtime the men relax around a fire, one performs a dance for the camera, and there is a free-for-all, before they return to work. At the main timber yard members of the contingent unload logs from a goods train. The men march back to their camp. One of the sergeants (seen only briefly) is a "Prince in his own country", probably Muti, son of Ntshingwayo, of the Zunga tribe of Zululand., Work of the South African Labour Contingent in France, 1917."
Hypotheses: As anyone that has ever worked as a forester would attest (I have), it is hard, dangerous work that requires considerable skill and coordinated team effort to produce usable lumber in quantity. IF a Continent of supplementary labourers were provided to assist a Forestry Company, over a period of time they would work well and efficiently together. The Unit leadership would prize that efficiency and productivity highly. If that relationship was fruitful, all efforts would be made to promote and preserve it. Noting in the IWN film (it is hard to see clearly) the apparent lack of unit insignia on the caps and uniforms of the labourers, other than the black NCOs with badges of rank, it would have been quite a coup and a boost to morale if unit badges were provided to the men, helping to cement the cohesion of the pieces that were cobbled together. As I said, a hypotheses.
So, here we have a unit, 32 Forestry Company working in the forests of France. We also have South African Labour Contingents working in the forests of France - at the same time (1917). Certainly, this is not proof, but hopefully a useful clue. The question- did they ever work together? More delving into the records and history of the CFC and the SA Labour contingents will have to be done to support or refute the hypothesis.
With kindest regards,
Tim