Great watch and the serial matches the early movement and so called "Poly" caseback. Also correct unsigned crown.
Lovely watch and a great place to start a collection. My second watch was the same but later serial.
As you know the case has been polished quite extensively and when you see the sharp edges of an unpolished case you will see the difference. The hands have been relumed so any change to make is to get them redone to try and match the original lume on the dial.
Enjoy it
regards
Paul
www.heuerworld.com