Vintage American B Model OS21C  EXCELLENT CONDITION SUPER TONE
24 Custom Walnut Buck Lumbert Chord bars 
               (Yes that's right, 24!)  
        Right now those 3 extra bars are set up as the 3 diminished 7ths...the only 3 there are , the only 3 you will ever need.   Playing with dim7s is really fun and they can be used especially for those songs from the the "Roaring 20's" and earlier. They are located on the 3 buttons closest to the players face in upright playing position, so they can be accessed with the thumb.   
Buck Lumbert bars are slightly narrower than standard 1/4in bars.   We use 3/16 felt and that works great for these....it meant that Buck could put 24 bars into the space that was normally occupied by 21 standard width chord bars.   THere is slight side to side jiggle on Buck's bars that is normal and sort of self adjusting.  It's it's own feel but works just fine.   
Standard Bryan Bowers Layout otherwise.
New Felt
New Scheiber Strings
Locked Anchor won't slip
Interior Soundpost for fullest sound.   
Strap buttons Installed.  
This is one PRIMO VINTAGE OSCAR