He has about 8 properties so he isn't the most seasoned mentor, but he has been kind and given me great information.  

@David FernandezTechnically your boiler is an HVAC system (heating), but I gather you are contemplating replacing the hydronic heat with forced air.If the property is in an environment where there is a significant cooling season, then the extra cost of switching to a central air handler (i.e. heat pump w/ ancillary gas for additional heat), removing the radiators and lines and installing ductwork may make longterm sense.If there is not a significant cooling season, then it would be far more economical to replace your old boiler with a new high-efficiency condensing gas boiler (~95% efficient).  

Some will have a shorter seasoning time than other but most of the time the less of the seasoning the less ltv percentage that will dish out Please correct me if I'm wrong but basically call as many banks and credit unions to ask what their requirements are.

Hello - Can anyone recommend a bank that will do a cash out refi on a rental property with no seasoning period?

I would start reaching out to lenders now and figure out what their seasoning requirements and LTV criteria are.  

So far, I've checked with two mortgage lenders and both require that the down payment either be seasoned (in my bank account for longer than the 2 most recent months' statements I would use on a mortgage application) or they would require documentation on the private loan and that the loan is secured by using my current residence as collateral.

or are there hard money lenders who will assist me with 100% of the cost and I can simply refi after the seasoning period?

@Mary Stead DocuSign is one of the big players when it comes to electronic contracts.

Would anyone have a preventive checklist on an excel spreadsheet with the type of repair to focus on and the months/seasons of work?

Example: A town's median income is 40k with a population of 8500, and sees moderate to low levels of seasonal tourism.