… saw this in the Oslo National Museum and now I need these keycaps – autohomouschair.
The caps resemble those of some Siemens boards. No wonder, according to this Deskthority wiki page Siemens STB switches were developed "to be used for keyboards by Siemens and its subsidiaries (esp. Tandberg)".
An alternative may be Devlin's Z series, and the profile also shares some similarities with the Triumph Adler caps we've seen on some contemporary boards: Fisk and here.
The IBM Lighted Program Function Keyboard (LPFK) was used as an extra input device when doing computer aided design on the IBM RS/6000 series of machines. Posted by epearl-tv.