Its a mix between Corris and TR days,
The cab is Talyllyn, without the plating on the one side, although this is probably more to do with an H and S issue. The round hole in the back is an original Corris feature, not carried on Talyllyn 4, which has a square hole with doors.
The frames are how it was in Corris days, with nothing below the tanks, unlike TR 4 which has (almost totally pointless) running boards.
The buffers are another H and S addition methinks, no central couplings, however the buffer beams are more like Corris Days. Much bigger than TR4's.
The air brake pump is on the other side, although in Corris Days power brakes had the compressor stuff mounted in the cab, hence the plating on one side. (Certainly on Corris 3, not sure about 4).
The cab spectacle frames are different to Talyllyn 4, not sure if they are based on the original Corris size frames?
Methinks the injector is also a bit different, certainly the clacks look different on Corris 7, I cant make out the gate valves on them, although this might be because they arnt fitted up yet.
As for the differences between Talyllyn NO.3 and the original Corris 1-3, well, its a totally new cab, different brake gear, different running boards also methinks. Not sure about other differences without looking at photos.
I imagine a simple reason for replicating Corris 4 in the new build, as opposed to Corris 1-3, was that No.4 steams a lot better than 3, is far easier to work on, is a lot simpler, and has more information avaliable on it, being a newer engine. Stanhope, is a very similar machine, so info can be derived from that aswell. Further to that, TR 4 is closer to the original Corris 4 than No.3 is to how she was build, more of the original to work from in effect.
Chris
Thats all I can see different for now...
