Here's a tested/fully-functioning Roland GR-1 Guitar Synth. This is an early made-in-Japan Roland, and features the expansion upgrade which offers additional storage space. These older units are best suited to curved, vintage radius fretboards - something to keep in mind if your synth pickup is affixed to a more modern, flat radius guitar. No box or power supply, but most any 9 volt/Boss PSA style adapter should work, and downloadable manuals are readily available.