Nice idea but i'd rather not go down the 650b route as i'd be looking at new wheels, brakes and guards. Given the lack of mounts on mine might be time to think about a better base for a chill commuter.
I always wanted more from my steamie and even though the geometry is a wee bit different, I felt the CC was then logical step . The build options are endless plus the ability to run up to 700x50 is fantastic. I guess the deal breaker is the canti studs over caliper (?)
Do a 650b conversion, with a 42mm tyre you've got roughly the same diameter wheel as a 700x28, then just fit long drop brake calipers.