Yeah, I did all of that (as I had already outlined in my previous comment), but it's still not showing up.Most mods are already .zipmod files - DON´T extract them, move them directly into mods/MyMods (you can create subfolders there for better managing, e.g. "cunihinx").
If you have a "hard mod" including abdata and userdata folder copy into your game folder.
With abdata and manifest.xml you can "recreate" a .zipmod: put them into a folder with a good name, compress it to .7z and rename the file into .zipmod. And up and away into mods/MyMods.
Why MyMods? Cuz Sideloader update will delete all mods inside the Sideloader Modpack folders which are not listed in Sideloader.