Not entirely satisfied with last night’s sketch (the arms aren’t as good as they could be, though they probably fit along the lines of the original art), I tried it again, giving the armor a little more attention:
Foreshortening was not my friend, but then again, it rarely is. That armor probably chafes his dorsal spine something awful. In order to make the sword/shield combination work, I had to lengthen the arms past the proportions in the reference images, but there’s no way that the original dragon could have wielded them effectively.