I did find Thomas Pryer at http://www.couchgenweb.com/civilwar/coe38
The info is the same as you have except that the unit was organized 8Jul1862 at Pocahontas, Randolph Co, Ark. all enrollments occured on this date and place unless otherwise noted. It says that little is known about the 38th except what appears on that page. Maybe someone else has some updates.
Best Wishes