unfortunately there are no Factory records for anything Fiat ...
Nor did they maintain any details of ownership or specifications etc
If you PM me have one of the largest databases of pre 1960 Fat 500s (including Jolly's) I can provide an estimate as to the month etc it was made....
I can ask my friends in Italy f anyone they know has ever encountered the car before...
There is information need that I ask for via pm/email rather than post on a forum....
It is believed that European Jolly,s were made to order and a car simply taken off the production line and converted as and when needed, but looking at US Jolly,s they seem to have numbers that are close together thus there is a theory that perhaps Jolly's for the US were converted in batches and shipped to dealers...