Hi, I have a wood doctor outdoor boiler that is about 12 years old. It is an xtra large I believe. I know it holds 300 gallons and heated 2 2000 sq ft houses. No problems with it, just tired of going outside to feed it. I just wanted to get an idea of what it might be worth in the real world...
At 12 yrs old it migh have 3 yrs left. I would not take a chance with all the work for a few more years of service.