Hi Bill
If you want to read more about the coins of Louis the Pious, you can do so here:
http://francia.digitale-sammlungen.de/Blatt_bsb00016293,00033.html
And there's an up-to-the-minute discussion of the coins of Charlemagne (up to 2014, at least!) here:
http://charlemagne.hypotheses.org/
you have to go to Section 5, 2 hours and 37 minutes
Lovely collection! All good wishes
Simon