Thanks for the link, Mosquito, and for bringing the pattern 'Herman' to my attention!
There is only a small (or a big) problem: the size of the pattern 'Herman' that is described in the link is 24,5 cm diameter. The 'Herman' I have here has (exact) a width of 34,5 cm and it has not grown over the years.....
Maybe a typo in the first figure or did Walther use more than one mold with different dimensions? Maybe a stupid comment, but I am new here and this kind of 'glass' is not my niche....
Thank you, Chopin-Liszt, for the welcome!