I did some last-minute testing and completed the hardware for now. Some small changes have been made to enhance the usability, like adding a discriminator threshold potentiometer back again. It's complete now and all the files have been uploaded to GitHub. I also added the components, details and files to this Hackaday project page.

This is what the final PCB looks like:

I'll keep you updated with project showcases on how to use the Mini SiD! The Kitspace page should also come online soon so you can order all the parts and PCB there.

Have a nice day ;)