IF you ever start a layout I am sure that it will be a pleasant surprise as I have realised that your modelling skills are top class! Now that you have collected the most of the desired rolling stock (that I am jealous of) it is the right time to begin. After all I believe that you are not the-model-in-the-box type...
Yes, it exists one in Pelion museum railway. Not exactly the same...but I had to figure out something small just to turn steam locos. Maybe it could be somewhere outside the layout, it seems to me now like a non-greek piece and I am thinking if it is better to move it. I am not sure if there is any one in the main network.
well done!!! The photo background looks extremely realistic. The shades of green and brown match those of the layout! I'm looking forward for a closer inspection ...