I would pay a little bit extra for the provenance (I'm a mad gnr collector) obviously not as much as I would if it was one of the band members. But it does have the name plate on and he obviously has the same surname as Slash. Maybe you could engrave the letters "S" and "L" next to Ash on the plate.
I notice Marc Canter is selling it for him. A longtime friend of the band who photographed and videoed lots of the early club days of the band. He's got a good book Reckless Road if you were a fan of the original band. I'm guessing selling this for Slash's brother won't endear him with Axl. Although Axl ostracised Marc (like he has most people) a few years ago around the time his book came out, much to Marc's disappointment.