Hi Humphrey, I am sorry but we do not have the dimensions of individual sections. To answer your question I would need to extrapolate the dimensions from a photograph and this would have such a wide margin of error that it would not be useful to you.
The Marlow wardrobes are supplied to John Lewis by a German company and the information you require is just not publicly available. Alas, this a limitation with such products being only available online and I appreciate the obvious frustration this may cause when what appears to be a very simple question can not be answered properly.
I can confirm, however, that the top is indeed flat and the overall height is 220 cm.