since I collected Cherry keyboards in the late 90s, I stored some in a box in my cellar. A few weeks ago I found a Cherry G80-1000 HAD, manufactured B02 (in 1989) - made in West Germany. It has 3 modes PC/XT, AT02, and MF and should work via DIN to PS/2 connector today.
It was not in bad shape, but the ABS was very yellowed since the time I picked up the keyboard (somewhat around 1998).
I read a lot about Retr0bright'ing the ABS, but most of the formulas are UK or US based.
So: what to buy in Germany? I looked for a German and easy option and went to a local shop for hairdressing supplies and bought "Cosmo, Profi-Hair" (Oxy creme 12%)
The case was nasty
But ... I was very much surprised and happy.
After cleaning off the bleaching residue I tested the keyboard. All keys work, also the LEDs.
Happy Retr0bright'ing, best regards from Berlin