I talked to the owner last weekend, and it has only has been in use two months. It is in the basement of a 10,000 sq ft building that is not well insulated. I think there are apartments on the upper floors. He simply needs more BTUs, and a bigger boiler is hard to come by, new or used. Stokerman has said that it also has an oversized ring for additional heat output. I can see the dust also, but you aren't buying the dust, it's free!. If you need a great EFM DF520, here is one with no wait.......it's in Ft Kent, ME, so that is surely more than a 'tank away' for most or us.
Sterlingman lives in the area, so if you wonder if it gets cold, just ask him. The weather channel says it's headed for -23 overnight.
I don't know what a new unit costs, but used units can get to 6K if they are in really good shape. Out of the NEPA the prices are different for the rest of us. Feel lucky if you can find good stuff for less money.
It's -11 at my house right now and my 1962 EFM 520 is silently heating my 3800 sq ft.
A 46 year old boiler working just like a new one; what is there to complain about? Quality is long remembered after the price is forgotten.