What was the '77 Grange like? It's my birth year (see @JohnM, not a millennial!) but noly heard bad things about the vintage. In fact pretty horrendous vintage world wide except for vintage port.
I had the 1976 a few years ago and it was wonderful. This 1977 not quite there, but hey it was still a nice wine and 40 odd years later still perfectly fine... It has port like characteristics on the after taste.
So yes, not the best year by Grange standards but still a very nice wine to consume IMO