Over the BB means no later than '84. Logo instead of signature seat stay cap means probably an 82 or 83. Likely an SL Professional or Corsa. Nice flat crown fork.

Number 2 on the left of the BB is frame size. Letter on the right is likely an E, not a D (most early 80's frames were E's). Sadly, Merckx frame numbers -especially in the early 80's- do not necessarily run in sequence and in most cases (especially early models) do not give you an indication of model. So Corsa or Professional, both great bikes.

Are you certain this has not been repainted? Head and seat tube logo decals are not typical for this period or color scheme.

Forget contacting the Merckx folks. They were less than helpful prior to being sold several years ago, now seem uninterested in assisting owners of these older bikes.