Congrats on that very nice find.....they don't come around that often. That one sure looks like you say "1980 ish"
For some comparison I have three:
1. a October 16, 1952 "Pre-27" with 6.5" bbl, Patridge front sight, diamond Magnas for stocks. Letters as shown. Shoots absolutely terrific!
2. a April 5, 1977, 3.5" bbl, ramp front sight, smooth GA target stocks. This gun is a handful to shoot with full load maggies onboard. Accurate but a bit of a punisher for me.
3. a May 8, 1980, 6" bbl, Nickel finish, Patridge front sight, checkered GA target stocks. Don't know how well it shoots as it came with a bunch of collector goodies, supposedly unfired except factory test, so sits in the safe for now.
Yours looks to have the Patridge front sight and I'm no expert but if a 1977 had ramp front sights, and the 1980 back to Patridge then maybe.
According to SCSW 4th, the 27-3 engineering change came about in 1983, and 1980 Target stocks became standard.
Any way you cut it...........you got a good one and please post a range report when you get a chance....these guns are phenomenal as to their build quality and accuracy.