It's quite odd how Henry has become so heavily associated with 'The Flying Kipper' train. I think it's implied in the original story that it's just his turn to take it, rather than it being a regular occurrence.

It only really becomes a thing in Book 27, where Christopher Awdry decided to specify it was the train Henry was pulling simply because it was a nice reference. Subsequent volumes pretty much confirm that it is Henry's train.

It's strange to think that such a widely known fact became part of the series so late on.

Before this, of course, Henry pulled the Kipper on the Tidmouth-Knapford layout. Personally, I like to think as many things from the layouts as possible should be canon.

Of course, Awdry really only had a choice of two locos in this case - Edward or Henry. From what I gather, the G&SWR 403 James was more troublesome than Henry! It does make sense that it should be Henry's train though, given he is the main line's goods engine.