One thing you could POSSIBLY do is use the ssw2rest converter that comes in the setools folder. For this you will need your firmwares' ssw file which im pretty sure u'll find at se-nse. I havent tried the rest that it generates, i tried to convert an ssw i got for FAR and it said "cannot convert firmware" i dont know why though. :confused:
The ssw2rest generates correct rest files(I used a lot of times).
For W810 you need to execute ssw2rest like this: ssw2rest MAIN_firmware 44140000