The Inter 10 is a great 531 framed bike and often sell under a true value price, so a bargain if you find one. The paint is particularly durable and build quality very high, these also tend to a longer TT which some riders prefer (or NEED). A-D (Puch Steyr) was a very early adopter of Shimano stuff in Europe, including using their dropouts on frames such as this but i don't think they were fitted with either a full 600 or DA gruppo, more of a mixed bag including some Huret stuff (like FDs) often mixed in. You can replace the damaged clip with whatever brand you like, I think the chrome of the DAs were very good but they don't need to be a matched trio. IIRC these were made from "imperial" dimensioned 531DB tubes rather than metric, true?