If your goal is to keep going and quit your job, you will need to leverage and preserve capital.

You can also call the city (without disclosing the address), and ask them about the situation, and if any part of it is grandfathered.This will let these plumbers cool off and likely not file any complaint because you're so nice, and they're still hoping to do business with you; it will also give you the proper information you need; give you time to plan and save up for the expense; and preserve your plumbing contacts.

This preserves rural lands but creates an artificial price influence too.  

If you open up your budget or are doing an owner occupied and can preserve capital it opens up a lot of opportunities. 

Some people don't want to maximize returns from cash flow, some just want a safe place to preserve capital.

Robert that has been going on for over a year now here.Some big funds have bought and pulled out but other funds have just started forming and are looking.Investors do not really have an edge but home buyers do in that many of the foreclosures are HUD or Fannie or Freddie with first look periods for owner occupant.So the hedge funds and wealth preservation companies are going after short sales with cash to get around that issue.

Wrap it into your mortgage so that you can preserve your cash for future deals.

Hyde Park is for wealth preservation, not wealth or CF generation.

It is in a great rental area and is a well preserved time capsule.  

You will meet your criteria for historic preservation as well as be able to control over all cost as much as possible.