He hasn't for quite a while afaik, way too time intensive to build by hand so he (at least last I saw 10 years ago) had a big batch made by a glass blowing company.
Yep, I no longer make regular Klein bottles. I'm a so-so glassblower. (Indeed, most glass workers would consider me a good physicist. Physicists would say that I'm a good computer jock. Computer people think that I know a lot about math. Mathematicians feel that I'm a good glassblower.