Interesting , as an OLD RT (1967-2000) I used Pr-2s, Pr-1s TV2Ps and Ap-4-5s for a long time. There even was a "infant" circuit designed, finding any of this material is near impossible today.
It is only for presentation purposes, for undergraduate students to have a look how it is actually inside. The design of modern vaporizers (not considering electrically heated) is almost the same.
You can convert it to other gases. You just need to clean it and adjust the marks to fit the % for another gas. If you want a hand on that I have my lab and I provide a certificate
