A "shop" could be anything from a rickety old printer and plotter in a leaky garage or basement to a 14,000sf facility like the one I work out of. Not going to get many inquiries or responses with such a vague description.
So what capabilities does this shop have? What does it all do? Signs, vehicle graphics & wraps, anything it specializes in? Do you have roll printers, flatbed printers, roll or flatbed cutters, cnc, etc? Do you just print, do you fabricate, install? Is there an existing customer base and a good enough reputation in the area for someone to start turning revenue? That's the kind of stuff people will want to know before you'll generate much interest.