Your best bet is to get a lawyer. 

I am sure early on in your career you`ve made mistakes and trusted the wrong people/professionals, and I bet that didn't prove you a bad real estate professional.

As mentioned, your best bet is to get an adjuster to try to assist on working with you to maximize the amount received.

Jesus only mentioned tithing to illustrate how hypocritical the Pharisees were but you can bet most preachers won’t preach it that  way .just like when you hear of the parable of the “ widows mite” preachers are quick to say it’s an example how we should do sacrificial giving down to the penny  like the old widow did when it was actually when understood in context as another example of Christ calling out the Pharisees and how they extort people !   

I bet the numbers look a fair bit better than here, I would hope. 

Should I just sell the renovated home and the lots and take the win, or manage the building of the duplexes and go for a bigger win over the mid-range (while taking on the risk that things go badly or the market shifts)?

Adam wins! 

So always project longer and more costs and if its less then its a win.

And I'd bet your 'Contractor' is not licensed or is not very good compared to typical standards...But good luck....

However, like winning the lottery, it could occur in an extremely small percentage of time.