they're great. a sport saved my life when a car hit me on it.
my friend just restored an international and it's a GREAT bike.
i've seen olympics and think they're probably about as good as an international depending on what shape they're in, unless they're better.
of course, with metal of that age, it depends entirely on the individual example. thinking of a conversion? may as well know how to relace and dish wheels, otherwise buying new parts makes the idea of a conversion a bad one.
I'm asking because I have a Gitane from the same time frame, and it just doesn't have a very solid feel to it. The frame is creaky and obviously cheaply made because the threads are flattening out all over the place. I rid a 63 or 64 cm so finding a good frame is rare for me.