To me it looks to have more drape than I would have expected from Cifonelli.
Simon Crompton's Cifonelli DB
I didn't find his write up about making of his Cifonelli DB, so I wonder if it is RTW.
Additional Cifonelli DB Jacket details (a different coat it seems) with a nice Milanese lapel buttonhole.
Simon Crompton in A&S and Hugo Jacomet in Cifonelli