I am trying to date a Burns Coffee Grinder

We just fixed and are now tuning up a Burns G12 coffee grinder. The thing is a beast, does three pounds a minute and it is mostly made of cast iron. It took two of use to get it on a pallet so we could bring it over to where we were wiring it in, and we had to have an electrician i to wire up the three phase power, but heck its only five horsepower.

The thing is we have no idea how old it is. It was patented in 1924, but that doesn't say anything about the actual date of manufacture.

Does anyone know anything about these things? It runs like a champ now that we figured out how to get the burrs lined up (I think the face was a bit uneven, or the burrs we have in there are a little uneven, one way or the other).

I will hopefully remember to bring my camera to work so I can take a photo of it, it really looks like its from the twenties. That and as I explained to Joe when he was wondering who we could call to fix it if it broke....

"Joe, anyone could fix this thing, its only got one moving part!"

If anyone knows anything about these I would be very interested in finding out more.