I have a web page with links to sites about coins of particular Roman emperors. http://augustuscoins.com/ed/references.html I just updated it and checked the links. (Unfortunately, many pages with links have lots of broken links.) A number of good pages have disappeared, at least with their former internet address. If you know of other sites devoted to the coins of a particular emperor, let us know and I will add them to that page. You might bookmark it.
Your web page is a really great resource. Lots of Kudos for all your work. Perhaps this site could be of interest? The Maxentian mint at Ostia: http://www.ostia-antica.org/dict/topics/mint/mint.htm