I'm trying to pinpoint the year my 64-3 was created. The barrel is not pinned so I'm thinking it's between '82 and '88 when version -4 came out, but I'd like to be a bit more accurate. The s/n prefix is AZD, and I haven't seen that in any of my research. Anyone have an idea? Thanks.

That Alpha tag fall into the range for 1988. While not listed specifically AZA and AZE show for that year.

Thank you sir.