Inspectors will assess the wiring and electrical panels for outdated components that could pose safety hazards, including fire risks.Plumbing issues like leaks, low water pressure, and drainage problems often arise as well.

They had to dig a 12ft deep by 6 ft wide hole to replace.

You don't have to put square peg's in round holes. 

If you have a drain stack that the 90 has cracked or worn a hole, then you could get consistent leaking at the point where it changes direction.

Stucco at this time (at least in my area) was poorly done with improper drainage and sealing. 

He secured all four doors with heavy deadbolt storm doors and fixed a hole in the roof. 

Who is filling nail holes?  

When you find yourself in a hole, stop digging.

Listening to the wrong people can put you in the hole fast.

If you where going to be able to recreate the orginal layout, you would of been able to do so by the clues left behind by remaining framing, be it the "honey" holes where the toliets once where, the sizes of the holes in the joist would indicate what pipes ran where be it hot and cold supply, toliets, showers and other industry standard tell tale clues.