The eventual buyers were actually in the property right after demo and kept coming back.

I forget what year that was, but the Metropolitan and Palace Amusements were still standing, although ready for demo (probably 2008ish)

And of course, you will need to verify before demo with a licensed architect or structural engineer.

Included demo and buying and installing 2 pre-hung metal doors - one with a half window and one just plain white (included door, framing, bottom threshold, hinges, basic knobs and locks).

Demo of the property may drive the cost too high to be able to build something that can bring in enough rent. 

If you want to go low tech, I would say to break out a section of the concrete there and see if anything is under it.Rent a demo hammer and mack a decent sized hole. 

For example, my bathroom demo and rehab, I see the end result in my mind, but I get hung up in little things in the process like hindsight, analysis paralysis, and reluctance to install something in the wrong order only to see myself having to redo it later and ballooning my budget out of control. 

I get to demo today, and I found the wall on the opposite side of the toilet has mold growing on the drywall paper.

@David Lehane Douglas and I are a good ying/yang on Frayser.  

Especially at the early stages where demo has been done and the new work is just starting.