I like the general idea of entry #17 but I do not like the font. Is that Times New Roman? Perhaps a more modern font.
I also like the idea behind entry #14 but the vertical height would make it impractical for certain applications. For example, a sign on the side of a building. Could the instruments be done on a diagonal or horizontally?
Thanks for feedback. Here are some more ideas. Using another fonts, rotating the instruments, adding a green touch. Hope you like it and, as usual let me know if want to see more changes or have more comments.