Hi, from what I have found so far three letter serial number prefixes starting with AB were manufactured between 1983-1988. In an appendix of the catalog I found ABA - ABD but the ABE's are missing? I just purchase a 10-7 in good condition with an ABE46xx serial number and wondered if there is any other way to track down anything about it? I know the model well having carried one as an aircrew member in the Army from the early 1970's - late 1980's.