After the window replacement, some cosmetic work, leveling, and rewiring the house will be livable and ready to rent.My question is after I finish establishing the new LLC and have the property transferred to it, how do I apply for a line of credit to afford all the work to be done?

If you have a boiler definitely don't change it is easier and cheaper to replace with another gas boiler then convert to electric. 

Tenant shall be charged for all repairs or replacements caused by Tenant, pets, guests or licensees of Tenant, excluding ordinary wear and tear.

Then an unexpected HVAC replacement put me over budget What made you interested in investing in this type of deal?

If I have 12 feet of cast iron plumbing, would you replace it or line it?

They usually come in about half that as long as they don't need all the windows and exterior doors replaced, but they can cost that much, so use that in your negotiations, that way even if the seller concedes to cover half, you might still get it all paid for. 

We also addressed some of the major components including replacing the roof and upgrading the external tankless water heater.

I envision Turnkey properties to be rent ready, fully renovated with all CapEx replaced and a tenant actively being placed.

Then facilitating design edits and renditions between HVAC, engineering, plumbing, back to HVAC, electrical, back to plumbing, engineering again, now hvac, engineering yet again..... yeah you get the picture.

I'm doing some initial analysis and have spoken to Engineers/Architects/System Suppliers, which has been useful in building a framework.I would really appreciate connecting/speaking to developers that have hands on experience with historic adaptive reuse conversions, to get advice on the good, the bad and the ugly, and find out what to focus on and what they wish they knew earlier.Thanks in advance.