I'm not sure there's enough room to make a profit for the owner, for you, and for an investor.I assume you mean the house will be worth $100K once it is restored to great shape. 

I am obsessed with 40's and 50's homes and would love to restore them to their former glory.

However, there are often some funds associated with them via special grants from certain philanthropic and/or governmental programs favoring the restoration and retention of what they consider historical homes/structures. 

Here is the story:As it happens I work full-time for a disaster restoration company, and a call came in from a lady who had a friend who was a hoarder.

What I do see is title flaws created by non-performance by the buyer and then failure by the seller to take proper judicial action to restore title and/or possession.  

For the windows, if they are the old wood sash single pane windows, it may be better to replace them than to restore them, unless you want to do a historical renovation.

You can often find some discount prices ar your local Habitat for Humanity Restore outlet.  

And there was a post on Zillow that suggested the cute little house could be "restored to its former glory."

Restore not read.

What I mean is I've heard of a Fire/Water Restoration company in my area that gets called in for an estimate on a badly burned house.