One can purchase a fretless guitar from several different places. Some of the places in which one can purchase a fretless guitar are: ultimate-guitar, Amazon, eBay, and fretless.

• John Cale used a fretless guitar on the 1965 album Stainless Gamelan - a very early recording of fretless guitar.
• Frank Zappa used fretless guitars on a few albums in the early and mid 1970s.

Gibson made a fretless, but a factory fretless isn't going to have the lines. Someone took a fretted and made it fretless.

The original bass guitar, invented by Paul Tutmarc in 1935, was fretless. Frets were not added until the model was innovated by Leo Fender in 1951.

Fretless bass guitar