Ovation Guitar Internal R&D Documentation - Guitar #73, Model 1687-8, S/N 0073

This is an internal Ovation Guitar Company research and development document dated 1976-1977, containing construction specifications and acoustic testing data for guitar unit #73, Model 1687-8, Serial Number 0073. The first page records physical measurements including top thickness, bridge dimensions, brace weights (totaling 233.6g), and deflection readings (RL, SN, K columns) taken on 12/14/76 and 6/8/77. The second page shows a frequency response graph (30 Hz to 9397 Hz) generated by technician D. Johnson on 7-11-77, with notes describing it as having 'excellent sound' and being 'best of the lot' among units #71-74.