You must have had one of them cheap suppliers - back in the '60s, many did the "baker's dozen" deal. Of course, we took that part on trust - just like, idiots that we were, we trusted that the product was "clean" and had nothing harmful.....
I got so used to hearing the 34 gram claim that it over-road the "sciency" part of my brain - maybe I smoked more than I remember.....