In the first part of the study, we sampled and investigated the composition of commercial glasses in the UK market from 2022 to 2023, as well as property data provided by various models. In this part, we utilize principal component analysis (PCA) to conduct a comparative analysis, integrating these data with the composition of commercial glass documented in previous literature. The widely held belief that the composition of commercial soda–lime–silica glasses has remained essentially unchanged over the past 30+ years is challenged by this research. The differences in composition of current commercial glass compositions compared to glasses from 30 to 40 years ago have been quantified. This not only sheds light on the direction of travel and reasons for adjustments to UK glass compositions over recent decades, but it also provides insights and predictions into the future trends.