I somehow missed this. FWIW, user adh1197 asked me for this back in February.

Anyway, I hacked up this control panel that works on System 7, but probably not System 6. If there's interest in System 6, I can fix it. adh1197 did the icon.

It looks terrible (I suck at UI), but should be functional. If you are UI inclined, you can tweak the DITL resource using Resedit to make it look a little nicer.