something to get a kick out of, a mouse hidden in each train painting. Terence Cuneo CVO, OBE, FGRA, RGI (1907-1996) was extremely gifted master painter, and was commissioned on every continent to paint particular steam locomotives, and he snuck a mouse into each painting

the above is known as "The Sole Survivor" and was sitting in a corner of the Soltau Shed, West Germany. The steam and action are added for effect, to give the abandoned engine a semblance of action page 79

after finishing this painting, he asked the railmen if he'd made any errors in operation, and had to change all but two of the trains, because he'd placed them in conflicting directions, rails, connections, and collision situations.  page 42

and he made mouse paintings, maybe for calendars? Maybe for the fun of it

         the right honourable Cornelius Caerphilly    and  the Right Honourable Percy Blue Vinney,

Dartaneo and the three mouse-keteers

https://www.bigissuenorth.com/centre-stage/2018/02/painting-power-art-terence-cuneo/
https://www.ebay.com/itm/Terence-Cuneo-1973-Digital-Print-The-Running-Sheds-of-the-Great-Caerphilly-/382878226243?oid=382818534147
https://www.preloved.co.uk/adverts/show/116620613/terence-cuneo-print.html?link=%2Fclassifieds%2Fall%2Fuk%2Fterence%2Bcuneo%2Bpaintings
http://low.onvacations.co/first-days-of-steam-by-terence-tenison-cuneo-railroads/
https://www.flickr.com/photos/peteredin/2851423727
http://terencecuneo.co.uk/?page_id=44

The Mouse and His Master: The Life and Work of Terence Cuneo by Terence T. Cuneo (1977, Book, Illustrated)

Cuneo (1907-1996) said he first sketched a mouse as a diversion.

He had been working on the formal painting of the coronation of Queen Elizabeth II when his Burmese cat came into his studio, toting a field mouse; he thought the tiny fellow would make a good ‘still life.’

Apparently when he showed the still life at the ‘Summer Exhibition’ of the Royal Watercolour Society, the attendees loved it and cried for more.

That’s when he decided to sneak a mouse—sometimes realistic, sometimes cartoony—into his finished works.

In addition to the numerous commissions he received from industry, he was called upon to paint portraits of Britain’s elite, including members of the Royal family—thereby he was named the ‘official artist’ for the Queen’s coronation. According to those who knew him, he was a kind and generous man.

https://mouseinterrupted.wordpress.com/tag/terence-cuneo/

there is even one that can be found in this train station... hint, click for full size, look on the right side

the Cuneo mouse is so loved and revered, it's even been painted on trains!

East Coast operated Class 91 (91111) at Kings Cross named 'For the Fallen' and in special commemorative colours for the commemoration of the First World War.

https://www.flickr.com/photos/sboothby/20308002820/

this specific painting was what got me looking into Cuneo's work, because in the book of his train paintings, some of them come with stories, and this one had the following:

The Capt of a British Navy ship in South Africa had a print of one of Cuneo’s paintings in his cabin, and one particularly educated guest noticed it, he asked the capt, "Did you find the mouse?" which was when the Capt was surprised to learn there would be a hidden mouse in there.

Well, the two of them looked at the painting, examining it carefully, and closely, and after many minutes of trying to find the mouse, they couldn’t.

So they did what any sensible person would do, and telegraphed Cuneo, who responded with “Up telegraph first right”. This message, unfortunately, was intercepted by military intelligence and reported as being “suspicious, probably in code”.

The Capt was visited to explain the suspicious message, and, this being a month later, he’d totally forgotten about the mouse. It was several minutes before he remembered, whereupon he took the interrogators into his cabin, pointed dramatically at a telegraph pole in the picture and said, “Here you are, gentlemen!"

At which point they all scrutinized the painting, and if you look at telegraph pole, first cross beam on the right, and there’s the mouse!  (thank you Denis!) 

If that won't expand enough for you, then look at it on the source, https://sworders.blob.core.windows.net/stock/523493-7.jpg?v=63716068260270 

https://londonparticulars.wordpress.com/tag/hidden-mouse/