I love my Davida lid....
Not cheap but I find it cuts most of the wind noise out, and while really tight for the first 2 weeks or so is like a glove after that.
And they have as British a heritage as your bike.
Gina
03 America - Pretty stock - except the TBS wheel...

06 America - missing, presumed in bits. With it's TBS wheel...

09 America - It's very blue....