You failed to mention the one true important thing, and that is what the actual problem is.
Such movements (whether new or vintage) have the same dimensions. They come in around 3-4 different variants related to the height of the hands (in relation to the movement and dial). A large size store will offer all the variants for this movement. Cousins most likely has all or most of the heights. So the movement can be easily replaced.
They can be serviced but usually no one bothers as the movements are cheap. And it depends on the issue, some can be fixed some can't, often time a new part or number of parts are required. Only indies might have such spares but, as I said, the movement itself is cheap.