I remember the taste of CDM being disgusting and just discovered it probably contains more ‘milk solids’ than cocoa (only 20%!). Though don’t know if the ‘milk’ ever came from what I’d recognise as a dairy. So possibly the only reliable bit of the appellation is ‘Cadburys’', which is hardly a recommendation.
Incidentally, IMO Bourneville’s appeal is far more architecturally/socio-historically interesting than the eponymous chocolate…