Call the number, if someone picks up build a relationship tell them what your plans are.

There are two types of equations I can run in Excel to estimate the number of payments left on the note. 

That is an excellent strategy.

I look forward to the building of future relationships.

Start networking and building relationships - people will help.

If I employed an agent who demanded I pay him before a deal closed I would terminate the relationship immediately and pay the commission after settlement.

That’s why it’s important to establish good relationships with lenders to avoid that risk.  

One of my business partners has a good relationship with a realor and so I'll see if we can work something out with them.

I'm open to setting an exit plan at ~10 years instead of 15-20(buy the investor out, sell or convert to condos & sell), but anything less is throwing away a lot of excellent cash flow from my POV.Any suggestions would be appreciated. 

@Eileen Murray provides excellent advice: take a day or two to observe similar cases.