Hi Daniel,I pulled out ye olde book of Stoneware for a look-see, then compared the line drawing to the bowl you were looking at on the aforementioned site. I am looking through the book for an image for comparison.
A cursory evaluation based on the line drawing says that the general shape is "close", however, there are a couple of points about the actual early 15th c drinking bowls recovered from the Parijse Hallen site that stand out.
1) the vessel tapers to a much narrower base
2) that base bears the "finger" indentations
3) the 15th c drinking bowl does not bear the small protrusions from the rim of the bowl that form handles that the modern one does.
Apparently the authors did not think it important enough to include a photograph of that specific bowl and I can find no others that match it. 
Jenn