Don't know if anyone brought this up before, but at http://www.movie-time.it/index.php you can find a list of spaghettis that this distributor apparently owns. It's like taking a peek in the vaults of a movie company.
There's not too much info, but both the artwork and the info on available languages are interesting. There's several rarities in there too, or English-language versions not available at present.
Of course, us common folks won't be able to see those original prints anyway...
some of the stuff I noticed:
english versions of:
AL DI LA' DELL'ODIO
ARRIVA DURANGO PAGA O MUORI
CON LUI CAVALCA LA MORTE
EHI AMICO, SEI MORTO!
LUNGO GIORNO DEL MASSACRO
UOMO CHE VIENE DA CANYON CITY
not available in English:
RIC E GIAN ALLA CONQUISTA DEL WEST
Also, there are several movies listed that are currently only available in poor quality.
All in all, they have a nice collection of some 100 spaghettis.