I would agree, i think a corporate design dept, would look more favorably and see your background as a foundation and value vs small firms that are (in my experience) looking for design specialists. As for age the answer to that is No it is not too late. I would also suggest that you make sure that you focus on some self defined projects that show your creative design thinking and ability to provide your background knowledge to making your solutions more complete beyond simply sketching and CAD.
But be careful and insure that the self defined projects truly identify a real problem and that your designs provide a real viable solution.