Help for downgradin dashboard firmware

[gelotus]

Hi to all, I've got an amarok dash for retrofitting in my polo 6r. That dashbord is a 2H0920871B 1009, my tools are unable to access it and I want to downgrade the SW to FL_2H0920871___0729_S.frf which is a public available SW and I have it. Tried to flash that file failed, I think caused by wrong security access key in the file. So I think I need the original frf of the cluster FL_2H0920871B__1009_S.frf that is not public for creating a custom odx file for downgrading. I'm in search for that file or also a prepared odx.

Thank you and regards

[Daku]

Not possible via OBD