It's tucked in the FM area on a UK site too along with some other good mag repair info in the service tool sections. Still see a few original FM booklets for sale online. FM printed and reprinted it for years with several different color covers, gray, brown, yellow, blue, & tan. They used this booklet in their FM mag repairman schools years ago. Believe the first edition of FM123 was 1945 with gray, black & red cover.