What is new is if all the mechanicals, plumbing, electrical, roof has been replaced.

This theory sounds good on paper but I know very few people to actually do this with success [except @Brandon Turner ].To complicate matters further, you are looking at an attached double, which are rare here in Indianapolis, that is zoned as two separate properties.As mentioned earlier, this defeats the "benefits" of having two doors under one roof/deed.In addition, this type of property is tough to resell in the future as well.I'd suggest passing on this one and whole concept - IMHO.  

Here are some general specs: 8 br/4 ba Over 4300 sf3 storiesMajority of the house outdated Lots of knotty pine ceilings and walls Unfinished basementMissing copper pipes (stolen last year out of the basement and never replaced)Roof 10+ yrs Well waterSeptic systemPond on property (large enough to paddle boat on)My plan of action is to first see if the owner will allow me to get a pest inspection that I will provide to a contractor and ask for a bid.

Central hvac, good roof and flooring.  

My plan has been to buy a fourplex (all four units under the same roof), be an owner occupant in one of the units, and put 3.5% down.

I'm sure it is optical illusion, but it looks like the roof is higher.  

New roofs w/i two years.

Water stains might mean a leak in the roof and/or bad flashing. 

But check the furnace, condenser, and roof to start with since those things are typically game changers. 

If you can work with the owner to let you do repairs on the house(like roof repairs so that the condition ceases to degrade) you could then file a mechanics and foreclose on that lien.