The $Sticky attribute pushpin and $Lock attribute adornment icons are packaged separately in the application bundle, making it easier to customise them. These files are stored at:
/Applications/Tinderbox.app/Contents/Resources/elements/
The files are of type '.icns', i.e. macOS icon files:
- locked.icns
- sticky.icns
- unlocked.icns
- unsticky.icns
See also—notes linking to here: