If the customer does not have a way to supply better artwork, and the image is not good for vectorizing, then the only chance is onOne's Genuine Fractals software that might be able to enlarge it and keep it acceptable. Genuine Fractals is the best software there is to try and enlarge raster (bitmap) images. If it can't make it look decent at a large size, it is impossible to enlarge it. You can download a free trial to see if it will do a good job on the image. If the trial software does a good job, you will have to buy the software to get an image without watermarks so you can then work with the image in your art department. Buying the software is not cost effective for one job though unless you can charge for the extra work to make the picture printable.