It's a different case style, guys. Yes, it looks like it has been polished, but no they did not bludgeon the lugs with a file like I think you're thinking...
Dial looks original (yes, measles, but all over, so some call that 'patina'). Hands are correct. Crown is a replacement. Crystal is likely original and with a loupe would probably have the UG crown floating in the middle as with Omega crystals. Those wedge magnifiers were OEM.
This caseback has the heavy stamped UG logo on the inside, so it likely had a very shallow reference and case number on the outside. It may still be there or may have been polished out (it's easy to do on some of them).
That movement actually looks to be in pretty decent condition. You have to get past the micro-rotor. Unlike with some watches, a dingy colored rotor does not usually mean that the rotor has been wearing against the caseback. Rather, the rotors were electroplated in a very thin layer of gold. Some of the old ultrasonic tanks and watch cleaning machines are particularly aggressive and can actually strip that layer right off. So it may point to a previous owner who actually cared for their watch and had it serviced. If it bothered you enough you could always have some 18K electroplated right back on, though the finish wouldn't be as pretty.