you guys might find this interesting:
When I was a kid, I recall seeing a few of these Zuckerman helmets being used by southern Oregon loggers. I clearly recall one that had the same letters SFP on the front (like the picture) and was painted an off-white (the other was painted a silver color)...not sure what that means, I thought it might have something to do with Sierra Pacific Industries, which is a forestry/timber products company, but that region back then was all Wyerhauser and Roseburg Industries.
I suppose those Zuckermans were purchased as surplus?