I contacted Keysight using their official request form on their website.
I'm a private person.
First answer from Keysight: They ask for official documents of my company as proof before they can respond to my request.
Seems I'm in a dead lock here.
Out of ideas at the moment, getting to catch some hours of sleep now.
I had that issue ordering a new meter face from them once. But as soon as I called them and told them I was an individual not from a company, they said no problem and sent it right off. It helps to actually speak to someone sometimes. I'd give them a call.
Thanks mtdoc, tautech, Cerebus and xrunner for your support!
My first idea was to sent them my certificate (graduate in electrical engineering, German: Diplom-Ingenieur).
But ehhh. Nonsense.
I decided to start with mtdocs advise of giving Keysight Germany a call.
When I told the Keysight representative that I'm a private person he answered that it's ok.
The Email I got was part of their standard procedure for requests from unknown Customers without company record.
I should answer to that email declaring I'm a private person and that would be it.
I was too daunted. Am feeling better now.