Hi Valerio,
our series is the Dunlop FHR Long Distance Cup (German: Dunlop FHR Langstreckencup). As they say, it is the world's biggest Endurance race series for historic race cars made after FIA Appendix K. And it is an official FIA approved international race series.
It offers the possibility to race cars from period E, F, G, GR and touringcars from period H. That means every car from 1947 - 1971 and also touringcars from 1972 - 1975 are allowed (but not the Porsche 3,0 RSR for example). Here is the link:
http://www.fhr-langstreckencup.de/The entry fee per race is between 750 € - 1000 € per race and to enter the championship, you have to pay around 600 € before the season starts.
Our engine has 158 HP and a torque of 181 Nm. And it ran already 10 hours on the dyno. With the cars weight of 669 kg it should go quite fast. Do you know your cars weight? I would love to see some detailed pictures of your Europa.
Best regards
Stefan