Can't you just use the innards of the old switch with the casing from the new one?
Or do you not want to risk trying to take it apart again?
I had one damaged by a vandal whilst the bike was parked. Got a replacement and broke the casing trying to get it apart, got another replacement and successfully took it apart.
The innards I'm using are the original ones from the V11. They had to be, because the second replacement had a different switch in it. From an Aprilia Scooter, S50, I think. Very cheap on E-Bay second hand. The switch had only two contacts rather than four, but the housing is identical.
Getting the switch apart was not that hard on the second go, after messing it up the first time and then thinking about what I did wrong.