I got mine from Classic Car Decals (CLASSIC CAR DECALS - Restoration stickers for classic cars.
) some time ago. I can't remember how much they were but a quick check on the website lists a price of around $US75.00 for a 12 decal set. I do remember them being very explicit - they wanted to know the year and model, R/LHD and body colour, so presumably this is their take on the decals used by Alfa at the time. That is not to say that they were all used on any particular model and I'm not sure how you would find this out. Maybe the Alfa archives might know.
My 1750GTV, a late model one, has been in the family virtually since new. The only stickers it had were the big lubrication chart, the red one on the radiator cap, the curved one on the air box, a paint code sticker in the boot and the AR Made in Italy sticker on the firewall.
I guess some of them were put in different places - I know the 'Made in Italy' one was on the firewall because it finally fell off a few years ago after about 30 years exposure to exhaust heat, but I've also seen it on the door jamb as in your picture.
The only diagram I've got is the usual one from the Instruction Book below, which isn't much help.
Regards to all,
PS: BTW paul_hb, I note that you don't seem to own an Alfa at the moment. Why the interest in the decals ?