I have a Group 23 green cap (I think that is the correct #) that I bought new at the Mopar Nats in probably 1989/90 for my then '70 340 Swinger. Never filled it, sat in box until last year on workbench shelf, took it to Battery Wholesale to check it out and it was no good. Probably as "near-perfect" as you could get - never out of box or in a car.
PM me a cell number and I can text you photos.
Richard