This is my original model and is my Saint Valentine's Day Gift to my lovely wife. It features a heart shape which is hugged by me (upper arm) and our son (lower arm).
This is a 2-color print and is sliced for my Prusa i3 MK3S + MMU2S. I used Overture Pro PLA Red and Pink with 0.15mm layers and, IIRC, default PrusaSlicer settings for everything else. It printed overnight 100% without a single intervention (I love my MMU2S!).
I suspect the music box mechanism is “standard” in that there are a bunch of sites that sell these. I found the song I wanted on Amazon for less than $10 delivered, but I'm sure you can find them all over the world for even less.
If you'd like to see how it looks before you print it and you have a phone that does AR, I've upload a USDZ file here. It looks awesome on my iPhone. (I'd bet Android has a solution too, but I'm unfamiliar with it.)
The author marked this model as their own original creation.