I think I remember his plate on his YJ being personalized say a version of ICEAXE. Is there a way in the US to search that?
Possibly, they are kind of public record.
LEO can run a plate, ( I do not have that access)
Some DMV's will tell you info for a fee and a form, it varies state to state.
and a handful of websites for a fee, but I do not know what all info is shared
Google image search of it, sometimes surprises you.
His username came up in a YJ forum, but was a mention top meeting him and a link to this thread.
* Edit, I also know how much his privacy meant to him.* So I am a little torn, you know?