Lost Engine Number!

[CraigAmor]

Hi guys
I have an Autotune Aristocat which many of you will know has Jaguar XJ6 underpinnings. I'm trying to establish whether the engine (4.2 litre) is from a Series I or Series 2 and for that I need the engine number (I can’t rely on the V5C as being a reliable source!). And I simply can't find it - perhaps you could give me an idea as to where I should be looking?
Many thanks
Craig