Key nembers on locks?

I've been in touch with Rhinoman about sorting out my immobiliser problem. I also need to obtain a key that will lock and unlock my doors and can be coded to my immobiliser.
Rhinoman has suggested I ask here about whether the key number can be found on one of the lock barrels of the car, which is a 2000 hardtop with the early, non-remote central locking by key.
If I can find a key number, I can get one cut online and send it off with my ECU/Immobiliser to Rhinoman for coding.
Anyone know if and where to look for a key number? I'd rather not pay the outrageous prices the nearest Suzuki dealer wants.

Often on the driver's door cylinder, strangely not on the ignition barrel. That is of course providing you have an original matched set of locks. Chris.

Thanks Chris, I'll take a look there after work. I've no idea, but no reason to believe they are not an original matched set.

HaHaHa I just realised, I wrote nembers, not numbers, Doh! Still got a helpful reply though.