FIngerings for wind instruments

Hi,
Fingerings for wind intruments look like this:

I'm planning to implement this feature in a near future, and so I'll explain my idea, and so if you could just tell me what you think of it, and how I could improve it, it would be really appreciated.

So I thought the easiest way to make it work for all instruments would be to have a small set of svg files (one svg file per instrument) and toggle the filling of the shapes when clicked.

I guess autoplacement of svg files is probably quite simple to implement. Maybe it's actually already implemented?

This is especially useful in methods and early music.

About saving the element, I'll still have to think of it.

Any comments and suggestions would be appreciated.