Hello,
Independent of the firmware your device uses, I would suggest to go straight to the bootloader procedure, which is described in this link, and update to the latest legacy firmware, which can be downloaded from here.
If your device contains RUT950 *G1*** in the product code, you will not be able to update to the versions RUT9_R_00.07.00 and above.
Keep in mind that this will delete any current device configuration.
Also, what do you mean with "that I will sign stable would be the best for this Reuters?"
Best regards,
Žygimantas