Engine Number Query

The engine number on my V5 is six figures XXXXXX
On the engine the stamped number is seven figures 1XXXXXX (the X's match the numbers on the V5). There's an additional figure 1 at the beginning of the serial number stamped on the engine.

Does anyone know why this might be? Is this usual Triumph numbering?
The bike in question is my 2005 Speedmaster 865.

 

Thanks for the info regarding the last 6 digits of the VIN / engine number.

I was mainly wondering why the engine number is 1XXXXXX and the V5 only shows 6 numbers XXXXXX.

I'm thinking about shipping the bike to the US / Canada for a three month road trip and thought their customs might have an issue that the engine number does not match exactly with the V5

 

I put my VIN number into the Triumph website and it cam back :-
Speedmaster
Manufactured / Registered 2005
No service options

So nothing reallu useful in that.
I'll have to see who the original dealer was (and see if they're still trading) not sure what they'll think if I do call them about how they registered bikes theyn sold 20 years ago lol