You have a couple options. You can bring it to a Graphics Specialist with drum scanner capabilities, though that would mean removing it from it's mount to wrap it on the drum and scan it, these guys are pros and there will be no harm done. You'll have a digital capture then of the highest possible quality, but expect to pay for that quality. They would also have the ability to output on a media of your choosing if they are a print capable shop. You could also take a digital photo, yourself or by a professional, of it and bring the hi-resolution file to a sign shop with print capabilities. Many sign shops now have large format digital capabilities and can print on a multitude of media, even on canvas. I have had prints reproduced before and digitally output onto artists canvas and they look great. It's all Dependant on the quality of the original capture, either a scan, or photo. There is an old printers adage " crap in, crap out", so make sure you provide a good quality original.