Thank you very much John!
So, it appears I wasn't too far off, good to know! What worried me the most was the need of a ferromagnetic core and, if this is not needed, but what is required is "only" a big fat winding, then no problems at all..
It appears that a very kind member over at ARF named Genoo solved my problem, as he sold me lots of TV goodies for a song. In this package there are some focus coils, so I should be ready to go building the monitor
Thanks a lot again for your help!
Best regards
Giulio Maiocco