So we received $450,000 less cash than if we took the all cash offer.We received a 1st lien note for $1,300,000 wrapped around the existing $650,000 loan.

Some web searching has brought "Property Managers Inc." and "Integrity Pro" to my attention. 

I am not encouraging you to act the same way, but if you are interested, I can give you the website of this company.Thank you for your attention.

and I will never receive any portion of the proceeds."

I never  received the money.  

And we pay attention to past addresses (for length of stay and how well they know this neighborhood) on the credit report.

In fact, in most states, Contractors are limited to receiving either 10% or $1000 as their down-payment, whichever is less.....You are right, 50% is something I only see for quick 2-day jobs with a crew like a fence install or roof replacement.

Or is there anything I should pay attention to during initial calls)?

Thanks to everyone for the education that I am ready to receive! 

I would be happy to show you around and grab lunch.