Hello Tom!
Even though the manufacturer is able to deliver new switches :
https://www.marquardt-schalter.de/pr...d8e134&lang=EN
I already bought a new and some further old switches on a radio fleamarket for a few Euros because it is like you say: It is always better you own parts you never need than looking for something. This is why I also bought a junk set for a crt and further compatible components like pots, knobs, tubes a HV transformer and so on.
Greetings Josef