I spoke with the owners today.
They said the mill has been the same weight its been since they have owned the new store. They also agreed it was once advertised as 1000lbs but not sure what has happen.
I do know as the story goes 3 years ago or so. Tommy (from IH) and MTW were sent a shipment. The mills were well under weight. They called there suppliers and the issue was fixed the next batch. If they could do it once they could do it again.
And here is the original original web site from David A before Aron. Ive done allot of home work on ths mill to know. Go to the frequently asked questions. It says the weight.
Industrial Hobbies Square Column Mill