Seumas is an LMS Ivatt Class 2 2-6-2T (Arthur's Class) engine built in 1947 during the waning era of the Big-Four railway companies. In 1948 he (along with the other LMS, LNER, GWR and SR engines) was absorbed by British Railways (BR) where he happily worked his remaining years before being withdrawn in 1966. But his story doesn't end there, He was purchased by the North Western Railway, where he reunited with his relative, Arthur.
@Domix258