Help identify the age of this Moet White Star

So i tend to buy older NVs when I can. I love old champagnes. I got several NV Champagnes at a huge discount from a local DC store from a cellar they bought. Its a Moet & Chandon White Star. Taste was very, very old. A smell I could live in for days. Similar to 1970s NV champagnes I’ve had before. This one obviously had more dosage which only really became apparent after about 3 hrs. Really nice aged flavors and basically flat at this point. However, the extra sugar made it a great foil for fish veracruz

I want to say that this is from the 1970s or 1980s, but I have no idea. The Cork only had Champagne written on the site along with OG, and a SGF on top. Nothing on the cap and only the NM-250-001 only the label. There is a light printing/etching on the bottom side of the bottle Hard to read, but I think its LGAYIG. Any help would be appreciated. Pics below.

Looks like it’s in really good shape; not sure about 70s in that condition

Seems it is from early to mid 80s on, depending on how long it aged in bottle.

1988 at the earliest. The Schieffelin & Somerset name dates from that year, when Guinness and LVMH formed a joint venture out of their US importers.

Mid-90s.

Picking up on this dormant thread, I’ve got a similar Q and would appreciate any insight on this label. Hard to find any real info to correctly date these older NV releases. Got this in Italy, curious to narrow the release range to a decade. I was told 80’s but suspect 90’s. Thanks for any help.