Note:  Models with the 1500 also had larger brakes all around, but still had
smaller rear axle.

yes, the axles nuts were still 36mm, but the shaft was the same length as the
64-67 ones to take the wider drums.  I drove a bus with one of these on it,
which had a couple thick washers to keep the earlier style drum on.  Don't
ask me why it had just one,   the  thing had been on Dead tour in the
seventies and was still bound to cover just a little more ground.

and when they had the big brakes, they also used the front steering knuckles
standard on the 64-67s.

Aug 63   1144282                        0578878       1500 Standardized

thanks for confirming this

Note:  This VIN intro'd the larger rear hatch and rear window, but still had
pull frt door hdls
Dec 63   1222500                        None Listed  Push Button Frt Door
Hdls
--- - - - -

what is also interesting is that the buses with the pull style door handles
also have the earlier style (elbow) engine lid braces, not the later spring
style ones. 

but my  (VW published for dealer use) books have slightly different numbers
than yours for the body changes (engine numbers are the same).  Curiouser and
curiouser, said Alice.