Bachmann class 108 roof.

Hi all. I am looking at buying the green class 108, 32-900A, when it finally turns up. However, I do not like the roof with the large indicator box above the cab. Does anyone know whether the roof will come off the body on the Bachmann 108? is it possible to get replacement roofs? Also, Ideally, I would end up with something that looked like the 32-903 108 unit, but in green.

Any advice welcome!