I have been sewing for about 12 years now and my focus area is Florence in the late 1400s. I have mostly explored sewing in the Society for creative Anachronism, though I enjoy other eras as well. I often find that I like making things from the transitional period between the era of the Houppelande into the later period fitted styles. Ideas were changing and the structure of society was changing, so it is fascinating to me to see that reflected in both art and garb.
I want to reproduce the brown Gamurra in Leonardo Da Vinci's portrait of Genivra di Benci which dates at the latest to 1478 which is two years before the cutoff, however the painting does not show much construction so I must look in the focus period for the actual form of the dress. That painting is where I get my details, but I will be referencing paintings from 1480s for overall construction. For the layers I would make a chemise ( layer 1), a brown gamurra ( layer 2), a cape ( layer 3) and the two accessories I know I want to make are a silk partlet and a silk coif with embroidery.
EDITED: I have changed my mind and will be recreating the gold dress (standing, centre) in Domenico Ghirlandaio's Birth of the Virgin, which dates to 1485-90. All other pieces will otherwise be the same.