Most people in the forums will mean well but most of the advice you're going to get won't be verified by an attorney and you don't want to make any mistakes in a delicate situation such as this. 

In that day, insulation was fabric wrapped wire.These 20's and 30's homes can be interesting architecture, buy REI's aren't architecture preservationists  (baring Queen Ann and Victorians), so you've got a major GUT and restyle project IMO.

At the time of purchase I was given a rent roll for one month which I learned after closing it was totally fabricated.

If you're not replacing it for insurance reasons, you could consider having it professionally coated with a hybrid system consisting of polyurethane-modified acrylic and reinforced with fabric.

Have removed all fabrics, carpeting, etc.

Have you considered just placing pre-fabricated tiny homes out there?

Not only that, it was illegal - it is a federal crime to abuse the DMCA in the manner he abused it.So here is the point - through his "Licensed Branding LLC" team, he "fabricated" an issue of "copyright abuse" in order to try an illegal take-down under DMCA.

There is a delicate balance there.

Abuse is a VERY delicate issue, and there are lots of resources for the abused, and friends and family supporting the abused, seek them out.

If you want to build, maybe don't build something on site, build it off site (pre-fabrication) and bring it on site.