While I could find nothing of the modern crostata anywhere comparable to the 16th century crostate...
I did hit paydirt on finding a modern equivalent to the period dish in France!
Shall I eat my words? Not entirely, because it shows we can still not generalize without the research to go with...
What I have found is that my take on the pastry used is likely correct rather than what the translator of the book came up with... like it's a contest, but seriously... I would rather strive for perfection than just take someones word for it (does that ever make me sound like a pompous ass!!!), it is why we must try recipes and do so from the originals. It is one thing to translate, to know about food and write about it but another to take it fully to the next step... these researchers may not have the time, but loads of readers do and you know what they say about many hands making light work.
Anyhow... may I introduce you to the (at least one variety of) "recette de Croustade" which explains quite well Scappi's Crostate Pastry!
Note: good luck finding the right modern recipe for the dough, easier to go with the original 16th cent. recipe, as this name refers to so many different dishes!
Try searching recipes for hand pulled strudel dough with only flour, salt, egg and oil, found one on the first try with google
From a real-estate site no less: http://www.french-property.com/regions/m
"But this traditional recipe can be turned into a more gastronomic version which requires much expertise and time! The gourmet Croustade looks like a delicate, airy eruption of thin crispy petals of dough.
The traditional recette de Croustade consists in "lightly brushing every paper-thin sheet of pastry with melted butter, yolk or goose fat and filling with warm, sweetened and flambeed fruits
The recipe of this Midi Pyrenees speciality consists in stacking thin sheets of a hand-pulled, strudel-like dough, but nowadays modern Chefs often use filo dough to go faster!
Layers of buttered and sugared sheets of filo are topped with sugared apples flambeed with Armagnac. Two other crumpled, buttered and sugared filo sheets come to cover the fruits before baking the preparation.
The secret for a shiny, golden brown topping is to dust the Midi Pyrenees Croustade with caster sugar and put it back into the oven for a few minutes."
There are differences however, you can't just go and find a recipe and re-create and call it period... but you could probably tweak it...
Some Differences: period crostate had a thicker pastry on the bottom (but buttered between layers just as the rest of the pastry) but had the thin pastry made into a pastry twist for the sides and the top being done in the same pastry but in different manners including the one as described above.
Also note: along with the pastry, his apple variation is also similar apart from the addition of layered cheese and raisins.