As works of art, I really like your guitar images. Trying to convince somebody that an object is in good shape is something else, however (as several posters have pointed out).
FWIW, when I put something up on a web auction (I do sometimes...), I always use a small-sensor camera to get maximum dof (you´ll have to dwn-res heavily, so resolution isn´t a problem). Also, I´ve learned the hard way the necessity of cleaning and dusting all surfaces scrupulously: every grain of dust and every fingerprint will show in all its glory...
Good, even lighting, but still with some sense of direction to get textures out properly. If there are scratches or blemishes, make them show clearly (without over-emphasizing them...); it´s far better that a buyer is aware of them from the start than if he finds them after delivery.... And, obviously, absolutely no clone stamping anywhere...
All that said, your guitar images almost make me want to take up playing....:salute: