Vintage and unused Trackmaster lever action reversing rheostat,  model R-20 for S and OO.  Copy of 1952 catalog entry shown in photos.  Ad claims "make your control panel look .... and feel ... like a real railroad control board...".  From the estate of a long time collector of American Flyer S-gauge trains, unused condition, original box, with either original or facsimilie copy of the installation instructions.