Under the hood, there is the serial number plate, usually found pop riveted to the right hand side of the hood latch.  This has the type of car, "330 GT" for all cars in this registry.  The motor type is also 209 for all 330 GT cars.  The last item is the most important.  That is the chassis serial number surrounded by stars.  Sometimes, '330GT' is stamped before the serial number.  On cars with A/C, the serial number plate is located on the sheet metal near the right front shock.

Four types were used by Ferrari during the 330 America and GT production.  Type 1 was used on the Americas and early (<~6400) 330 GTs.  Type 2 was intermixed with the type 1 in the early 330 GTs.  Type 3 was used from ~6400 through to the end.  Type 4 was intermixed with type 3 from ~8500 to ~9100.

Type 1 (horse only)

Type 2 (MADE IN horse ITALY)

Type 3 (MADE horse ITALY)

Type 4 (horse MADE IN ITALY

Type 1 GTO Engineering

Type 3 Italian Car Parts

The left cam cover has a plate on it that shows the firing order along with the cylinder numbering scheme.

Note, the FERRARI 209 area  should be as shown, i.e. not wrinkle painted.

The air cleaner top has a metal plate that specifies the type of FISPA filters to be used inside. 

The early models with the open sided air cleaners use the curved plate.  The later models with the air cleaner with intake tubes use the rectangular plate.

The 40 DCZ/6 carburetors each have a serial number and type plate on them.

The 40 DFI and 40 DFI 2 carburetors do not have plates.

GTO Engineering

Each fuse block covers have a plate that describes what each fuse controls.

The most cars through ~8275 used 12 fuses while from 8279 on had 16 fuses.

Some interim cars and early 2HL (before 8279) had an extra 2 fuse block (14 fuses) for the electric windows.  The cover for that block did not have a plate on it.

The air conditioner (if so equipped) has a plate on it.  And yes, this York compressor from Borg-Warner is the original that Ferrari put on for the factory air conditioning.

The brake master cylinder has a metal band around it.  This master cylinder dates from Oct. 20, 1964.

Here is another master cylinder with a plastic band around it.  The band has VB 80025 on it along with a Sep. 9, 1965 manufacture date.

Kilimanjaro Designs

The steering box has a serial number plate on it.

Each distributor has a plate on it.

GTO Engineering

This A/C hose has a band on it.  Each hose's band has its Borletti part number stamped on it.

080.4231.006 - condenser to dryer
080.4231.106 - dryer to evaporator
080.4211.202 - evaporator to compressor
080.4221.105 - compressor to condenser

Most 330 GTs came with FIAMM horn sets.

The compressor has an aluminum plate.

Compressor

Kilimanjaro Designs

Each horn has an aluminum plate on the top.

Horn bulb

330 GTs sold new in France would have had a plate installed by the French importer, Franco-Britannic-Autos.  This one is installed on the rear of the sheet metal covering the left front shock in the engine compartment.