if there is no recent FW for your box, you can easily modify one from e.g. Ovislink/Airlive. All you need is a HexEditor. Original FW exists of five parts (BIOS, Rec.Loader, Kernel, RootFS, GUI). Each of these blocks is marked with a blockheader. In this blockheader one can find two relevant strings (e.g. Conceptronic):

0000000: 4c4c 4d5f 5255 5330 3031 0000 0000 857e LLM_RUS001.....~\\
0000010: 5175 6565 6e00 0000 0000 0000 11e1 6bc7 Queen.........k.\\

All you have to do is modify the "LLM_RUS001" part according to your device. If the brandname of your box is shorter, overwrite left characters with zeroes. Unfortunately, the checksums won't be ok after this modification, so the GUI update page won't accept this "hack" but the recoveryloader does!

BUT: Allthough the GUI suggests a different brand, your box is still the old brand internaly, so the GUI still only will accept orig. FW files from your orig. manufacturer! Upgrade files (only consisting of kernel and rootFS) will generally be accepted by all brands!