You owe only $38,860 to pay off your loan now, possibly less.
From what you say about your loan, tell me if I got this right:
30 year loan
$75,780 original loan amount
9% annual interest rate
$609.74 monthly payment
You have made 272 payments
Payment number 273 is not due until late 2019, possibly early 2020
If I have correctly figured out what you have done, you have been making monthly payments early by pulling out payment coupons before they are due and sending them in with payment. You are about 4 years ahead on your payments.
If I have this correct, if you called the bank and asked "what is my payoff amount if I want to pay this loan off tomorrow" they would answer something like $38,860. When you pay a loan off early, you don't just owe the sum of the coupons still remaining. In your case, you owe at least $16,000 less!
Indeed, if there is some way to convert your 4 years of pre-payments into an early payment, you would owe even less than $38,860. I don't know banking law well enough to know if that is possible.
You should stop pulling coupons out of your book and paying them early. Any payments you make between now and when your next payment is actually due (late 2019 sometime?) you should tell the bank you want applied as an early payment. This will bring your total owed amount down much faster than pulling coupons out of your book and making payments years early.
If there is someone in your family who understands banking pretty well, maybe they can help you sort this out. I don't know who to refer you to for more personal help, but I really do think you have more than $16,000 to gain by changing how you are paying your mortgage.
Good luck!