"Made in USA" stamped into wood in back of peghead beginning 1969. Another dating feature of Gibsons is the use of a peghead volute found on instruments between 1970 and 1973. Also, in 1965 Gibson switched from 17 degrees to 14 degrees on the tilt of the peghead. Before 1950, peghead thickness varied, getting narrower towards the top of the peghead. After 1950, pegheads all became one uniform thickness, from bottom to top.