There is no budget for electrical or fixtures...which in a home of this age you will surely replace. 

Use similar comps; number of bedrooms/baths, stories, style of house, age, quality of schools/district, etc.  

Age of the asset, number of units, there are just so many factors if you are trying to gauge upside, you need to consider them all.

Congratulations on taking such big steps at a young age.

You are doubling your transaction side exposure, adding far stricter license law regulations, stricter accounting regulations, billing & bidding approval processes & much much more.By all means give it a go but the age old phrase you don't know what you don't know looks like it's going to bite you in the butt here.

With the age of the property (1820s) you should definitely be more conservative.  

The real potential problem with a mastiff of that age is not the injury it could cause to a person, but to the damage it could do to the property.They do loose bladder function as they age, and they have a large bladder. 

That might mean you could dispose of the property in total only after that gifted element has aged sufficiently to get 121 benefits for the entire sale price.

They have four or five children ages from 2 to 7.

We are all taught from an early age to go out there and get money, to make as much money as possible and that once we are at that very high level of lots of money ONLY THEN can we really be happy.