Good points. I think the reason this is complicated is that the Apollo missions included one stage, the S-IVB, which was used twice, for getting into low earth

Good points. I think the reason this is complicated is that the Apollo missions included one stage, the S-IVB, which was used twice, for getting into low earth orbit, and for departing for the moon. You have to count some fraction of that as mass lifted to orbit, but i don't know how much.