This looks really cool. I want to use them to make breadboard layouts for kids to make synth circuits. Unfortunately when I tried to open it I got an error that it couldn’t find the parts. It looks like it refers to a whole lot of .fzp files in your documents/fritzing/parts/contrib folder…
Could you make a zip file of those?
Some of the obscure parts, like the switch you mention, were made many years ago and I only made it so far as it worked for my needs. I’m sure I only used it once!
All of the parts are working but some might not work on the breadboard as I only use Fritzing to make PCBs so I never even look at BB view. Feel free to modify any parts that might be useful!
Hopefully these will do the job for most DIY synth folks.