This is one of those ironing board 15-strings, isn't it, not the next step up from a 12-string (a 5-string with two octave strings per base string). I'd take off the middle string, defret the treble half of the fretboard, and have a seven-string fretted alongside a seven-string fretless (B-F), like a bionic Ashula, then I'd never touch it again.