That is a beautiful set and the 2 trains are great replicas of the originals. Its a coincidence that I just received half of this set, the black one with the Tanker and Wagon. The original fictitious Black Steamer was released in 1961 and this 40th Anniversary set was released in 1999, at least that is the info I can come up with. If I am wrong I hope someone will set me straight. I think the box is very special and love the chronological pictorial of the original trains on the inside of the flap.
Great addition to your collection Sun.