James, as nitrocellulose lacquer ages, it tends to recede into the wood, giving the instrument a duller appearance. To simulate that aspect of the finish (especially on polyurethane), you could use some “super fine” 0000 steel wool on the guitar body (try it on the backside first, to make sure you like the effect). Areas where more wear is desired can be more aggressively rubbed. I would strongly suggest removing the pickguard assembly and all the hardware before using this technique, as tiny metal particles will go everywhere! You could also use 1000-grit emery paper, but more care would be required to avoid sanding all the way through the finish (the surface "clouds" up quickly, and you cannot see how far you have gone). Use a vacuum or compressed air on the body and neck before reassembly. As far as adding other surface blemishes, it is against my nature to intentionally mar an instrument; however, the rounded edge of a heavy crescent wrench does come to mind! Best regards, Dana