I'm assuming your number plate looks something like "xxx xxxD" so yes, you do have a 1966 car. However, unless someone has fitted a later engine, this car should be fitted with a 1570cc engine. Your chassis number should begin with 10503.
Take a look at the top of this thread
and you'll find the diagram you need (possibly in colour!) in exchange for a small donation to the AlfaBB. Alternatively, you could call Motorbooks, Pooks, Mercian Manuals, Highwood Alfa etc etc to see if anyone has a workshop manual - but these will be in black and white only.
Do you have any photos to share in the Spider section?