This engine model was first built as a 2-8-2 Mikado (with running gear derived from Scotnick's 2-10-0 Decapod 9F) before having the front pony truck removed and a 4 wheel bogie from set 10194 (Emerald Night) added instead, turning it into a 4-8-0 Mastodon - type. The rear pony truck was removed as well, with the 79111-style boiler shortened and cab re-arranged.
Together, these several different engines from four different eras and four separate builders come together to create this one steam engine.
The cab features several gauges and a firebox door.
The coal tender was inspired by Anthony Sava's Pacific 4-6-2 model's oil tender with the letters "BRS" added in the middle of the tender using printed 1 x 1 tiles. The cab should say "6519" in the same type of tiles.