Yes it was from before there was a distinction, but that doesn't change that it was a measurement of mass, since they didn't have the conceptualisation of weight in the sense of weight being distinct from mass. From a historian's perspective, it's appropriate to label it a (largely) obsolete...
I have never before related so much to a character. For reasons. Private, smug reasons. Though I've never had a session end with a surprise homophobic parent before.