My insurance says they will not cover the vehicle and the roof damage will cost less than 1000 (my deductible) to fix.

You get the benefit of a great neighborhood and a comfortable lifestyle with no hassles of upkeep or grass cutting or roofs blowing off, etc... 

Seller is saying that nothing is wrong with the roof, new electrical but it does need the wiring finished, new plumbing and cosmetic.

@Matthew ReumI’m also new to REI but I think that what he means is “capital expenditures” which (correct me if I'm wrong) include new roof, new water heater, and other BIG expenses that don't happen every month.  

In Worcester they have what is called ZERO LOT LINE where you can share common walls with someone but everyone is responsible for their own exterior maintenance and roofs. 

But....My counterpoint would be it’s going to sit vacant until you fix it, or you’re going to get a substandard tenant willing to live with the leak, or you’re going to lower the rent for the new tenant.

Or a pipe or water heater has been leaking for weeks?

I'm not sure how to proceed, are there gas leak detection specialists I can call?

@Deborah Repaskey Buying a house that is 70 years old is getting better every year, one of the biggest issues with older homes tends to be knob and tube wiring or plumbing that isn't copper, both of these really started to be changed to modern standards starting in the 50s so that decade can sometimes be a mixed bag but those are going to be your primary concern unless someone hasn't replaced a major system like a roof in 70 years. 

I prefer to put every line item down with almost an exact cost so I can get hard numbers and have the % returns based off of those numbers, not the other way around.If I walk into a place with brand new roof, furnace, windows, kitchens, bathrooms, with quality construction, plumbing, etc...