Hi it's a 3646 Autavia 3rd execution probably around 1968-1969. Not sure about the hands...pic's too small for me to see.

Dial may clean up with the right watchmaker on the job though discolouring of the subdials is common and can look ok. Crown should be signed. Bezel is correct for this model.

I hope I'm correct though I'm sure if I'm not others will correct me (glad to be corrected)!

I have the same watch...hopefully the movement is in good nick. That's pretty important. These are really great watches and wear well on the wrist being bigger than the 36mm Carrera's from the same era. They are also on the rise price wise...

Good luck with the sale. Have a look at the OTD price guide.

Nathan