If, as the last picture tends to suggest, there is a dark patina in the bottom of the engraving cuts that would figure. The cuts appear to be angled and quite sharp so would patinate differently to the stamp. The 800 stamp is much broader and the fact that it is stamped gives it a profile that would tarnish differently to a hand engraved cut as seen in the dedication. It is also feasable that someone has cleaned out the engraving at some point in the last x amount of years. I'm still fine with it. I don't see any problems with the style of script either.