I watch Shop Goodwill regularly and see the crinkle machines all the time. 27s, 28s, 127s, 128s, 99s, and 66s are what I see the most.
I've seen one pic of one crinkle FW, and to my memory haven't seen a crinkle 15 at all.
Lots of Whites, Kenmores, Domestics, Franklins and some others usually made by white in the 40s and 50s too.
Joe