Dvaravati refers to a Mon Confederate Kingdom in what is today Central Thailand, though at times it is believed that their rule extended from parts of Eastern Myanmar to Cambodia. They issued a number of coins, of different styles in both Silver and Gold (though mostly silver) and some members do in fact have coins from the issuers in their collections. It is, from the looks of it, a significant issuer that has been left out of the catalogue and I think will make a great addition to the Issuer list. For currency, it would be helpful if it had a Ratti system like many of the other polities near it at the time.
Wikipedia page:
https://en.wikipedia.org/wiki/Dvaravati
(Note the Victorinus Antoninianus on that page).
Thanks,
Rajbarage