Yes.
I'm building mine from a big basket case (there's stuff from three bikes - two B models and one A).
So far, I've found a lot of detail differences but everything seems to be interchangable.
Some differences are obviously just updates (like the later brake pedal going over the footpeg, rather than under it and the shape of the fuel tank) while other things are obviously part of the ADR process (levers with brake-light switch included, horn brackets etc).
But yeah, they're basically the same bikes.