Well, it's certainly possible there were some buildings there as late as that, but I doubt the Dirt Factory buildings are that old. I walked past there today, and bushwhacked behind the quarry in grass way up past my head and then back along the creek. Flushed two partridge, but didn't see anything that looked like ruins. There's a fine new beaver dam, though! I came out where the historical sign is, and all I can say is that it had to be in a convenient place along the creek. The rock people have dumped huge piles of rebar/iron back there, and I imagine the land has been altered quite a bit over the years. 

That barn the Dirt Factory has is pretty cool, though. As well as the tall yellow barn where the auto body place was.  I think they were pretty clearly a single farm. (You can walk all around it on the new hiking trail (which is also the Ramstad snowmobile trail in that stretch.) 

I'd love to go snowshoeing along the creek when it gets solidly frozen to see if there's any evidence along the creek bed.

Yeah, you know, most roads that used to exist around here you can at least find a footpath where the road used to be, or at least see the clearing between trees. I essentially followed that road path today (to the northwest of the buildings, nearly exactly)  and found nothing to indicate there was ever a road there. Like, it was mostly rough hummocks of mud and swamp grass. If it was summer, it would have been muck up to my knees and impossible going. I think the quarry land-moving has swallowed everything up. 

Thanks for the aerial photos. I spend so much time with old maps, that I forget to look for old aerials.