I have photographed the originals on my spares car
Be aware the original label supplier or (more likely) Fiat or the component maker themselves will own the copyright in such labels, so you may want to consider changing the style and/or wording and /or colours before sending anything to a potential supplier. Copyright infringement is unlikely to be a concern to private individuals, but an established commercial firm may be a tad more sensitive to the matter.
Two points occur to me: first is, warning and safety stickers are widely available commercially, and inevitably on eBay, so is there something off the shelf that might suit? (though I imagine you've checked this already)
and secondly, have you thought of contacting Fiat directly to see if they hold any NOS items? Alternatively, bodyshops might be a source, since they must replace labels appropriately when repairing crash damage.
