pretty positive this is Nervesa, who has made much of the older Cifonelli pieces in the past
according to A Harris, around Zegna/Caruso level of construction. I had one Cifonelli piece that would attest to that
Labels can be seen in this ebay listing
Also, I'm pretty sure that Kosher only refers to food and that fabrics are non-shatnez
When AngelicBoris went to Martin Greenfield for his wedding suit a few years back and told him no linen in the collar,etc. because he was Orthodox, Mr. Greenfield scrawled Kosher on the ticket.