I have just finished rebuilding my 1994 Marinoni Special, and I'm having some trouble with the rear derailleur cable housing. The cable-stop on the chain stay is not the modern type, which accepts a standard ferrule. Rather, it is a small, spherical braze-on with a hole drilled through; a hole exactly the diameter of the cable housing I am using. If I don't use a ferrule on the end of the housing, it slips through when I try to shift - no good. On the other hand, modern ferrules sit against the braze-on and create an abrupt and problematic change of direction in the cable.
I am sure that there was a specific ferrule made for this application back in the day, and I just need to find one. What is it called? What does it look like? Are they still available from retailers, or do I need to scrounge in the misc. parts bin at the local bike co-op/used bike centre?
Thanks for you help!