The Thunderhead was the top of the line Storm series guitar.  The body of spruce and maple was adorned with gold hardware including DeArmond pickups and a unique phase toggle switch.  The model shown below is a 1968 model with Vibrato in the dark nutmeg finish.  This was my first ever Ovation electric guitar.  The guitar has held up wonderfully over the years and still gets frequent use.  The bound neck and diamond shaped inlays look brand new.  On this particular guitar the vibrato tailpiece has been modified into a solid tail with out spring, even though it still looks every bit like a vibrato model.  Click HERE for specifications.