Do you think it's capped? That was popular in the early 60's with the karters.
I screwed up on ebay about a year or so ago. I saw a Jumbo Jr. Ashtray. It was a new 3.50 tire like my Bug, with a glass ashtray that fit in it with a tire dealers info reverse painted on the glass. It sold for like $15, I was watching it but forgot to bid.