This is one of the surviving "double-herm" statues showing Metrodorus. A 1st century Roman copy, I think.
This inscription (the left one) says Ἕρμαρχoς -- (Hermarxos, Hermarchus.)
This appears to be the bust that the left sketch was taken of. Some websites record this as Metrodorus, but again the inscription makes it clear. This is Hermarchus.
I'll see what I can find about the righthand sketch.