Wanted Black keys for A500 Mitsumi Keyboard

[jurassicman]

Hi all... long shot here.
I got an A500 black keyboard with some missing keys (don't ask me why...) and I would like to buy them.
The keys I'm missing are visible in the following pictures. Please contact me if you can help.

 

[screemo]

Hello, I think you would more luck with just getting a new set from a1200.net - I assume the black keys are from a CDTV keyboard?

 

[jurassicman]

@screemo sure, a complete set would be an option but don't want to spend almost 100 euros for that. I already bought a new membrane spending almost 40 euros.
Let's see if someone can help.
Honestly I think that the keys are from a1200.net and not from a CDTV keyboard but I'm not sure about that. Is there a way to recognize the manufacturer?