I'm not real sure what Kye is looking at (Sorry Kye) but I defiantly don't see any model parts on the HG Noble.It all looks to be model 2 parts to me.
I think you are comparing the HG Noble cylinder to the HG Palmer cylinder and yes they are different and the HG Palmer engine was more based of a Model 3 engine.Which is a completely different casting from the Model 1 & model 2.
Ahh ok, I thought the HG noble pictured in my post might have had a Model 1 exhaust. I didnt quite understand Rufastoo's post when I read it. All good.