the engine number on a factory engined cos, should be 2 letters followed by 5 numbers, the same digits as the last 7 digits of the VIN plate, the 2 letters before the last 5 numbers denote the year and month it was built,


for example, a escos VIN starts WFOBXXGKAB NL 12345
shows that the build date was october 1992, and the engine number is 12345. the engine number should read NL12345.

there is a decode table here to work out the year /month letters....


http://www.btinternet.com/~madmole/vindecoder.html