Moin Moin !
double brake circuits
since August 1963 for all 110/111
disc brakes on the front
220 Sb / SEb since April 1962 , all others August 1963
exterior mirror on the driver's door and a new chrome ring/horn ring (no more circular) for the
steering wheel
I dont know.
But you are sure , if you open the engine compartment. The bulkhead has a flap until 8.63 , you can open it for getting the heat from the engibne direct into the heat exchanger , if this ist frozen.
The clutch cylinder ist in the engine room mext to the brake cylinder. There is no brake booster , if the car has one the booster is in Front under the battery pack and is driven by hydraulic.
Further the car sky is material and not plastic, the hood latch changed.
Sorry, my slightly english is not used for more than 50 years......
MfG Volker