A basic contract price will not allow them to make enough to keep their business running between typical job delays, weather etc...., so they will take on another job or two to keep their cashflow going.

I don't think the issue is with it being historic directly, it probably is more to do with conditions associated with the age.

the tenant (single mom) was living there for 6 years and tenant had kept the property in great condition. 

What condition is the property?

I didn’t want to create a novel in my original post, but I should have mentioned that the other tenants are using the storage under the same conditions.  

House is in good condition, with a relatively new roof--single owner for the last 50+ years.

For HVAC, A furnace and air condition replacement assuming no ductwork required would run about $5000 around my area but varies widely.

Here in Dallas/Ft.Worth area the local market conditions are such that landlords do not provide washers, dryers, nor refrigerators in the units.

Unless you’re really comfortable assessing home conditions, don’t take the risk.

1) Did you know of the condition in 2019 and the condition of the house now?