I had a couple of watchsmiths in US by phone tell me that they did not work on "junk." But after I brought my rep in to one of them and they looked at the movement, they did in fact service it.

So you might be better off just taking it in and telling them up front it is a rep and has sentimental value to you and would they mind taking a look.

EDIT TO ADD: do not try at AD, but I figured you knew that.