No real information for you, but just an oberservation.
If your ancestor made that trip to Missouri with Price and came back, that is a story in itself. He was also "as tough as a boot" to make it back.
You may wish to check the 1889 Goodspeeds for his home county for the man's information. If a person rode on that trip, I have noticed a man usually said it in their write-up, if they had had submitted information.