1960s Mr. Peters Batwing guitar with the patented Sceusa assymetrical neck

The most immediately obvious design element of this 1960s single pickup electric guitar from Mr. Peters Guitar Mfg. in Santa Ana, California is the Batwing shape on the treble side of the body. However that is not the feature that makes this guitar really interesting, for it is the prototype of Peter Sceusa's patented "Sceusa neck" (Patent 3,091,150) that later appeared on several Rickenbacker guitars.

In cross section, the Sceusa neck's profile is asymmetrical with the thickest section being behind the bass strings, so that the back of the neck tapers from the bass side to the treble side. The concept was developed to allow the player to fit the neck to the arch between the thumb and forefinger of their left hand. In practise it is said to have worked well enough for those players who like to hook their thumb over the fingerboard, but for playing barre chords with the thumb at the back of the neck it posed problems.