@Harrison CookYour post kindles lots of questions.In the "good old-days" most heating systems were vastly oversized for the building they were heating - energy was relatively cheap, insulation was non-existant to poor ... so it was easier and safer to {drastically} oversize.Today, while energy {in North America}  is still relatively cheap for the moment,  we have a much better understanding of how to make buildings more efficient {though you might not think so looking at the construction industry in the U.S.A. and Canada}  and there are often more cost-effective measures than simply replacing an old, over-sized heating plant with a new, over-sized heating plant.You really need to - or at lease should -  perform a heat load analysis to properly size your heating system, a component of which, is determining the rate of heat loss of the building envelope.  

Give us the answers to the questions that @Michael Plante asked and we could better help. 

@Michael Plante Check with the mobile home dealerships in the area as well as your local manufactured housing association.

He was a self-taught engineer who founded a company that built plywood plants all over the US. 

Working class neighborhood next to a plant or factory, maybe? 

@Michael Plante I think there's a couple possible reasons for the scenario you described (which I agree does happen frequently)

As for busy streets, consider a fence or planting’s to create a break.

@Michael Plante , I agreed that it seem like a lot more than I had initially prepare for.

It might be a bit cheaper, but the real savings is if you don’t have to replace plantings, sidewalk, driveway, etc.

Thank you @Michael Plante and @Nathan G.