1.   Freedmen took the name of their former owner, so this is Caius Lucius Tigranus, once owned by Caius Pomponius and now known as Caius Pomponius Tigranus.

2.   PLAUSTRUM is the Latin for Cart.

3.   The symbol for sestertius was IIS, as it originally stood for two and a half asses.  The S was the half.  For simplicity, IIS then evolved into HS.

4.   A Roman numeral with a line through it is multiplied by 1000.  Hence D with a line through it is 500 thousand.