I've seen DDR machines stateside that have had the coin counter rolled over. They don't earn nearly as well as they used to, and most of them that have seen that much play are pretty beat up, but they used to make absolute bank. That Dancing Stage is in pretty good shape for 400k+ coins, probably better than mine (which I think has somewhere around 600k coins on the counter but may have rolled over), and I've done a fair bit of work on mine. The operator must have actually cared enough to clean it now and then, and the players must not have abused it like seems to happen here in the states.
The SSR code is LLLRRRLR on the cabinet selection arrows, btw
Works on 3rd Mix (Japan and Korea regions). Other regions and versions used other methods of getting to the highest difficulty (called "Expert", "Maniac", "Heavy", etc. depending on region and version).
Finding official arrow panels is darned near impossible outside of Japan. Betson in the US *might* have official ones, but they probably have the same knock-offs from China that everybody else has. The knock-offs aren't bad, but the material is wrong (it's stiffer and tends to shatter when it breaks - probably some sort of polycarbonate material whereas the originals are Lexan) and the silk screening on the underside isn't nearly as robust. They also sometimes need the corners trimmed to fit which is easily done on a bandsaw with a slapped together jig. I have a set of them on my machine, and while they feel a bit different, they're waaaay better than the worn out originals I got with it.
FYI, a simple vacuuming out of the insides of the stage does amazing things for the performance of them, and doing so frequently prevents wear and tear. Generally no need to go crazy cleaning everything, but it doesn't hurt. Be careful that you don't break the CCFL lights; they're a bit expensive to replace and are fragile.