Hee hee, guys pretty much 95 percent or more of all repro arcade art available is unlicensed. Actually, the ONLY licensed artwork to my knowledge is the Pac/Galaga stuff available from Twobits.com
The arguement that copyrights somehow helped gaming is sketchy at best. Atari made Pong, and then every gamemaker around made exact copies of it. Yet that is exactly what started the video game revolution.
Whole games were commonly bootlegged from the early 80s to early 90s. Yet those bootlegs really didn't have too much of an effect on the manufacturers. Arcade manufacturers are largely in the business of selling hardware, not software.
Lets imagine that the Williams Vs. Artic court case had gone differently (Williams sued Artic for their bootleg of Defender, and Artic argued that games couldn't be copyrighted because they were different everytime). As far as I know that was the court case that actually held up arcade game copyrights.
Ok, so anyone can copy any game. What would the results be? Easy, I can tell you. The games would have had better protection on them, and that is pretty much it. Sure, the bootlegs would be out there, but how much demand would there be for them 12-18 months after the game came out (and after the original manufacturer stopped carrying them).
Anyway, all of that has little to do with anything. If you want to print your own marquees and sell them, then go for it. But really, you are going to make like what, $5 each profit on maybe 6 of them? Forget it, just upload the file somewhere for others to use.