Sprint Sprint Rs Engine Number Query

Hi all, I have a Triumph Sprint 955i RS that I picked up a couple of weeks ago and wondered if anyone could answer a question for me.

I read somewhere that the Engine number should match the last six numbers of the ViN on the Frame but my engine number, both on the log book and the actual engine don't match the ViN does this mean that the engine has been changed at some point? I have no history with the bike and the previous owner wasn't aware of any engine change.

 

Me and the bike are still getting used to each other and I don't trust her yet. Done 200 miles so far without missing a beat though. Not having a true idea of the mileage the engine has covered (clocks claim just 20,000) I find myself wondering Is she getting noisier?, Is that clatter normal top-end engine noise or camchain knackered? Are the valves in tolerance? etc. etc. Sure I bought her from a guy who is a mechanic and knows his bikes and he told me he had changed oil and filter, and replaced the forks seals but he got it in a trade with a mate and I don't know what sort of life it's had. I guess I am a bit paranoid as, when I was younger I was sold more than a few lemons that I had to take as there was no choice for the cash in hand.

 

It's on a little kind of moulded plinth on the clutch side of the upper crank casing behind the cylinder block.

 

That is good to know. Maybe mine is the original engine after all.