The second of the tiny AE fractions. This one the larger of the two, though by all reasonable standards it still qualifies as tiny.

11x10 mm. I've checked Wildwinds, and they barely have any options this small - and none of them match my type.
I can read [ANTI]OXOY, and (at least) two more letters in the next line, one of which is H and the other looks like a H turned 90 degrees - which, depending on the font, can be Ζ or Ξ or even something else. I can't make any sense of it, though... possibly a date?
I apologize for the photo quality; in hand it's slightly more legible. You might need to turn the contrast up.