HP6236B Power Switch Replacement

[2N2222]

I have recently acquired a HP6236B. @German_Engineer had remembered that I was after one and notified me that one was for sale on a local auction website.
The device seems to be a fairly "new" one, the newest date code I could find was 8917. We had such a device in our school lab already in the mid 1970s and I am surprised that it was obviously still produced over a dozen years later. The only noticeable modification compared to the early versions is the missing pilot light.
The device works well, a visual check of the meters shows that they are spot on.

Only the power switch, although it still works OK, feels worn out and wobbly. I fear it might fail at any time.
I looked up the part (S1) in the parts list in the manual. There are manufacturer and HP part numbers given, but when searching for it on the internet, all results point back to the manual. I could not find anything useful.

Does anybody know how to get this switch or a suitable replacement?

Any hints are welcome.

[jonpaul]

classic HP dual supply we have several sincem1989s.

Switch  is a USA made C&K, switchcraft any similar 0.250" miniature 250v 1 a switch can fit and work.

Jon