Roman Replicas

So I was a little bit curious about how the Romans made marble copies of the Greek statues. Metal (mostly bronze) copies made a little more sense to me since then were just poured into plaster molds. According to this brief article (http://www.metmuseum.org/toah/hd/rogr/hd_rogr.htm), to make marble copies they would cast plaster figures of the original and then take exact measurements. 

I thought it was interesting that they would add other elements to suit the patron's taste. Much of what we know about Greek sculptures are from these replicas which could be very far from the original. Furthermore it was interesting to me that they had to add supports to marble copies. In my opinion, something as simple as a support added could ruin the entire aesthetics of the original piece even if they are beautiful in their own right.