Yup,a lid was an ounce but could weigh less or more,the lid measurement wasnt exact grams it's where the 4 finger measurement was used to determine bag size.
Back in the 70's ounces were $30 & a lid was $20,i would always try to buy lid's over ounces because both were very close in weight,$10 bucks was a shitload of cash in 1970