For what its worth, you can often find 'specification sheets' for callebaut products online. Just search for "product name specification".
The spec sheet will often include both the % cocoa mass and the % non-fat cocoa solids.
You can use these spec sheets to double check your calculation technique for 'extracting' the relevant info from ordinary nutrition information.
Finally, several of the Callebaut dark chocolates are made with cocoa mass, defatted cocoa powder, sugar, vanilla, lecithin. These are not high end single origin chocolates, rather middle of the road mass market ingredients. These chocolates are very, very thick when melted and have relatively poor texture, but are quite nice for doing things like make ganache where the extra flavor hit per unit fat is a benefit.
Also, in your example you have "1. 56g total wt". But the nutritional information is based on a serving size. For Dagoba bars the whole bar is usually 56g but the serving size may only be half of that. Was your example using Serving Size from the nutritional info or the total size of the bar?