At the reenactment this weekend, I also saw and played a number of Cooperman whistles. The tin one I bought for $4, and it has a oddly shaped block of wood for the fipple that is crimped into the mouthpiece.
This critter will never be anything like a favorite to me, but it plays very much like a Clarke. Its very breathy and chiffy, and for that it has collector value to me.
The wooden Cooperman’s I played were equally unimpressive, but workable as something to play around a period campfire and not look too out of place. The trader asked me to come back that evening and play, but the grounds were hot and muggy, and after dark I wouldn’t want to be there in non-period clothing. In that heat I really felt sorry for those who WERE in period!