Wow, you all seem very knowledgeable and after years away from the HO train seen, I am very, very green.
As for the Hogwarts train I believe it is the one that Bachmann US made but all it says on the bottom is "Bachmann", "Made in China" and a blurb about the rights. Also, yes the tender is completely missing but the train runs without it so it is not one of those conjoined units. Additionally, some of the train couplings need to be replaced. I am not at all familiar with the style of couplings. They are very delicate looking, consisting of a horizontal almost D shaped loop with a pin that lifts and drops in place when another coupler mates up to it.
As for the Hogwarts train I believe it is the one that Bachmann US made but all it says on the bottom is "Bachmann", "Made in China" and a blurb about the rights. Also, yes the tender is completely missing but the train runs without it so it is not one of those conjoined units. Additionally, some of the train couplings need to be replaced. I am not at all familiar with the style of couplings. They are very delicate looking, consisting of a horizontal almost D shaped loop with a pin that lifts and drops in place when another coupler mates up to it.