Ok, music sleuths...
My 1909 vintage "Jacobs' No. 1 Amateur Folio for Orchestra and Mandolin Orchestra, Banjo Solo" (which is where I've been getting all my Weidt stuff), has a strange version of the treble clef (G clef). This is simply your basic G clef but it has an added bar or 'strike' thru the clef, right at the staff line for the D note.
Go here:
http://www.classicbanjo.com/tutors/WeidtCollection/Weidt.pdf and look at the first three tunes for an example.
My question is: What does this indicate? It doesn't seem to affect the time signature, key signature or tuning...I've found it in variations of all of those.
So? I'm stumped, please enlighten me!
===Marc