|It is definitely a bad idea to try using a firmware update from a different model. At best it will refuse to install, at worst you could end up with a useless piece of equipment.|
I can't find a trace of the model you mention, and unfortunately Bush is one of those generic names that came with other labels on identical products. If you have managed to find an official Bush website with the alternative firmware on then you have done well, as it isn't an obvious location, and if there is a 'support' link on there I would try that first, after double-checking the model number of your hardware.
"I've always been mad, I know I've been mad, like the most of us..." Pink Floyd