Getting close to a source for f85r2

[Mark Knowles]

The Council of Basel was from 1431 to 1437(when it was moved to Ferrara by the Pope, though it continued afterwards)
The Council of Constance in Konstanz on Lake Constance(Bodensee) was from 1414 to 1418

I associate the rosettes folio with a later journey to the Council of Basel. Though the author(s) may have visited the city of Konstanz on route to Basel. Any visitor to the Council of Basel would have spent some time there.