I'm not saying it can't be made to work, just that there are a lot of differences. The fuel line and disconnect is different, and the plug is different. You've got an interesting project. The 1050 ECU is WAY different, so your 955i may not play well with the sensors and configuration. You might get away with flipping the fuel rail around (you can't use a 1050 fuel rail. Different injectors.) and if you figure out which sensors are which you might make it work. Or do some bodging to get the sensors from the 955 to approximately the right places on the 1050 airbox. Don't try cutting the airbox for "more flow." That will muck up things pretty bad and it won't run right. If you do have to make some cuts to make the airbox fit, be sure to seal up the holes, but I don't think you'll have to. I think your biggest problems will be getting the sensors right and making the fuel pump work.
That said, I have seen 2005-2008 1050 rear bodywork and sub-frame grafted to a 955 tank, and it looks pretty amazing. You may have to do some seat modifications though. If you have to go that route don't feel too bad. It also looks great with a 3:1:2 exhaust system.