Having read a number of references to Fra Angelico in a number of books (ok, mostly Ann Rice books, but it seems like he was mentioned elsewhere, too) I finally decided he must be a real painter. I’ve read references that basically said that he was one of the finest painters ever, and that his paintings are deeply moving, particularly his Annunciation, of which I have seen a number of different versions.
Evidentally, much of his work was in monastaries, in the cells of the monks, and so was not actually seen by more than a handful of people for centuries. I have not been able to find out if that is literary license, but it does seem clear that he did in fact paint a lot of frescoes in monastaries, so it could very well be true.