Well, a great start is the newsletter link itself that sent you; I'll add what information I can glean from it to the article. Yes, a blog or website of Franz's would be a terrific additional resource, which we can use subject to the guidelines on self-published sources. If Franz were to be interviewed by someone like Bryan Stroud or Jim Amash for TwoMorrows Publishing's Alter Ego or Back Issue, for example, that would be even better. I'm sure both of these comics historians, among others, would welcome the opportunity to speak with him!