People are talking about bpa, that’s not what I’d be worried about. Not to rain on OP’s parade, but I’d be highly wary of plastics from before 1978, a lot were made with lead. There were significant amounts of lead still going into plastics into the 90s before they really improved monitoring/regulation. Google for “lead in childrens toys”

Personally, I might use some plastic objects, but not any that touched food/drink.