@Christopher BerggrenYou appear to be complicating  your analysis.  

Nothing more complicated than that.

But it will get a little complicated if the place is under LLC.   

Yes, it is a complicated thing to explain. 

Something built in 1920 and something built in 2016 have a huge bearing on your risk.2) How complicated are the systems?

And @Bjorn Ahlblad brings up a great point about sellers (and even more so, brokers) tending to overstate by a grade or so.But now things are even more complicated in that using Lennon's grading scale a class B property could be built in 2002. 

Would any lender lend that 25% to me or is that too complicated of a deal?

We just assume the septic is bad and add 35K extra into our rehab estimate (though the last septic we put in cost 50K--complicated pump up system with mounded leech field due to high water table on site--so the difference came out of our pocket).

I really do enjoy the content this website puts out, but I am a little disappointed in how complicated this simple thing has turned out to be.

@Michael Stanley Nino  Investing from a distance is not terribly complicated, however it does require some travel and some hands-on activity.