When your looking to make a potential purchase of any Cosworth, you need to make sure it started life as what you think it is.
There is 3 places to look for to identity a Sapphire Cosworth that I am aware of:
-The chassic number will be stamped on the id tag on the shell on the slam panel under the hood
-the chassis number will also be stamped into the floor, you can see it by lifting a flap next to drivers seat
-the engine number is stamped onto the block under the exhaust manifold
On the ID tag you can also find out when the vehicle was produced , transmission type, and other identication features.
The chassis numbers depict's what model the car is, part way through (before the numbers start) is the code you're looking for. ie: GBBFNC is Sapphire 4x4
Sapphire Cosworth Vin numbers should start with WF0FXXGBBF, then the year and month code and then the sequence number. For example March 1988, which is 'JA'. Make sure it's the same on all the chassis numbers, including the chassis number under the flap next to the seat. Make sure the stamps are all nicely aligned. If its not aligned well it could be pointing to that at some stage some undersirable work may have been completed on the vehicle.
The VIN plate should have N5 as the engine code.
The cosworth car manual states exactly what the Vin number codes mean as per below:
It also shows you where they are located on the vehicle:
Another quick visual way to identify whether the car is a 4wd or 2wd is the petrol flaps.
The 2wd cars have a flap that you can flip open with your finger then a locking cap, the 4wd cars have a flap that you cant flip open.