Although the most likely species by far is Zodarion italicum, I assume you have already ruled this out.
The best summary of Zodarion for Western and central Europe is in the BAS Bulletin, Bosmans, R. 1997. Revision of the genus Zodarion Walckenaer, 1833, part II. Western and central Europe, including Italy (Araneae: Zodariidae). Bull. Br. arachnol. Soc. 10 (8): 265-294. Z. vicinum is in the BAS Bulletin Snazell, R. & Bosmans, R. 1998. Zodarion vicinum Denis, 1935: New to Britain, and in newsletter 81 with figures, Newsl. Br. arachnol. Soc. 81: 8-10. There are figures of Z. fuscum in Askins, M. 1999. Zodarion fuscum (Simon, 1870): a spider new to Britain. Newsl. Br. arachnol. Soc. 86: 11. I can email these to you since they are not SRS News issues on this website. PS, if your Zodarion is not adult, you will not get to a species.