On my continuing trip through the St Gall archives, I come next to MS 14.
The manuscript contains five books from the Old Testament (Job, Tobit, Judith and 1 and 2 Ezra). It contains notations in the hand of Notker the Stammerer, the biographer of Charlemagne. It dates to the 2nd half of the 9th century.
As an illuminated manuscript, it's about as minor as it gets; it makes the list because of exactly an interesting initial on page 1, and it's a pretty minor initial at that.
Here it is:
It's a zoomorphic initial, a fish shaped into a letter "C" with vegetal ends. "Fish letters" were a pretty common Merovingian motif, and lasted well into the Carolingian period. This is a pretty typical example. The titles are hollow capitals, filled with green and red. There are a few other hollow capital initials, filled with red through the manuscript, and that's about it for this manuscript. Perhaps useful, in a minor way as a model.