Selling or leveraging current notes?

[Tyler Mutch]

Hey group,

Looking for some advice here, I have a couple of first lien notes on two separate investment properties owned by an investor in my local market. 

One of the notes is for 9k @ 20% interest only (150 a month), the other is 12k @ 15% interest only again (150 a month). The trouble I am having was that originally the terms were supposed to be for a year (expiring September 2021), then we verbally agreed to extend to March of this year. I understand the flaw of doing it verbally. He has been on time with the payments and I haven’t have any trouble collecting the cash flow. I am currently trying to refinance some of my portfolio and would like to have more cash on hand so I am looking for options to either sell the notes with no real defined repayment period (I’m speculating he will need another extension come March) , interest only payments, or find a way to leverage against them (if possible). 

How do I go about valuations for these notes? 

What else should I be looking for when looking to cash out on these notes? 

TIA