That's a really cool project!! It's always fun to get see parts of history and how everything worked without the technology we have today. Like you said, these places would have been highly flamable with all the dust. I'm pretty sure a lumber mill in B-C had a devastating incident of that sort and most workers got trapped in a quick burst of flames and nobody could do anything about it. I went to see an old coal sorting mill in one of the last wooden tipples left in Canada a few years back, I really enjoyed it, your photos kind of reminded me of this trip. Thanks for posting!