The specific page you’ll want is http://www.immat.aviation-civile.gouv.fr/immat/servlet/aeronef_liste.html;jsessionid=7553258D865D1006E30A7B7FC598AB38?CTRL_ID=344487_528c953f – but when you search against model, make sure that you enter Sioux rather than Souix. Although it occurs to me that if it has been registered in France, it might have been as a Bell 47 – so a search against both might be prudent.