I don't think you need licenses for people's names. Names of humans aren't trademarked. I'm no lawyer, but I wouldn't think this is the issue.
Why it is not reading as the true LeMans participants... unknown. But that's a shame, because the detail on the 787b otherwise is outstanding. Also a shame because I've met and talked to J. Herbert about the 787b a few years back. Like you Ernst... I'm guessing we're both rotary fans. And I'm pleased to report, he was an absolute gentleman and a pleasure to talk to.