The Grade is a "F", "S" or a Number (1-7) stamped above the gauge number on the left corner of the frame water table


http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=90463

Last edited by skeettx; 12/18/17 12:06 AM.

USAF RET 1971-95 [Linked Image from jpgbox.com]