Interiors are comparatively modern though except for old doors and cabinets which I disclosed for lead paint as well.   

I certainly do not want to modernize it.

Hi Cade,BP has a Rehab Estimator tool which you can find under the Tools tab along the navbar.Another thing to consider is JScott's Book on Estimating Rehab Costs which includes a spreadsheet template that you can use.Otherwise, I have also uploaded a spreadsheet to my BP fileplace which has a repair estimator tool and a database of common material items and prices that you can use as a starting point.https://www.biggerpockets.com/files/user/drobertson/file/house-flipping-spreadsheet-6-liteOtherwise, there are web based apps that have similar functionalities to the spreadsheets that I could recommend if you are looking for something more mobile?

Lucky that modern faucets don't need washers replaced much, if ever.

If I were building, or rehabbing a home, i'd look to build a nice 3 bedroom 2 bath at 1800 square feet, with great floor plan, quality kitchen, modern baths, and hardwood floors. 

It's worth browsing just to see what you can and can't do, like TC-21-16 - Single Family Dwellings in Mobile Home Districts.

Need help turning my duplex, mobile home and transportation business into a LLC.

NKY/Cincy is my hometown and will always be the one constant place I visit as I am/have been geographically-mobile for my career; that's my simple justification for starting there.  

Mobile home university is a great place to start

Even if you start off smaller with a four unit, the demand is there if you own clean, modern units in good locations.