At first I thought it might indicate that your game is a sample or prototype, but they would not have production tags or stamps.

I think it has to do with "allocated" serial numbers on the assembly line. For example ;

Domestic had SN 0001 - 2500.
Euro had SN 2501 - 3500
Australia had SN 3501 - 4000
South Africa had SN 4001-4500

But they are only allocation number based on the country of export and not the actual numbers ?

They may have only made 2000 domestic machines
They may have made 250 Euro machines, but STARTED the SN allocation at 2501 and stopping at 2750
Then the Aussie run started at 3501 etc etc..

That's very interesting. Makes sense, thanks Nino. It really makes it hard to confirm actual numbers produced for these old games doesn't it.