On a CD 121 Hemingray, the engraver sure had a bad day.... Would you call this

MAY 2 1899

MAY 2 1893 {'3' engraved on top of a '9'}

Or??? ...

Interesting, I see a

[093] (F-Skirt) HEMINGRAY (R-Skirt) PATENT/MAY 2 1899/[Blotted out embossing] {Note 'MAY 2 1899' date} SDP

listed... I'm not sure what the blotted out embossing might be, other than the "mess" around the 9 & 3?

This is the best close-up photo I could get. In person, it's still not clear... I guess from "the mess" one can assume he perhaps tried to correct it, from a 9 to a 3?