Engines of the LNER Trailer

(Rated G for General audiences, meaning people of all ages can watch it. This is an video discussing a piece of history from the London and North Eastern Railway.)
Time to go a (sort of) different route. Being inspired by Amtrakguy365's Engines of Amtrak series, I decided to do something like that, but about the locomotives of the London and North Eastern Railway. For this, I've partnered up with my friend Stuart of Glenlow Works in the making of this series, and he's been a great help with sourcing the info and photos of the locomotives that will be seen in the videos.
Now, the locos I'll be discussing will be limited to Group Standard (Designs adopted by the LNER upon the 1923 Grouping.) to Peppercorn's designs. (Designs like the GNR Atlantics, North British Reid 4-4-0s, and Robinson's Directors will not be discussed. Sorry.)
That being said, the first locomotive I'll be discussing will be one of the most important of Gresley's locomotives:
The Gresley A1s and A3s.
(Music by Gustav Holst)
(Models by Camscott, edh6, Victory Works, Matrix Trains, Dovetail Games, Armstrong Powerhouse, MeshTools, The Welsh Engineer)