Does the sentence
seem grammatical to you?
Answers need not be limited to “yes” or “no.” Maybe you want to answer “okay, but strange,” or something else. That’s fine.
FTR: To me the sentence is only grammatical on the reading that has it meaning “We met to discuss the subject of 10:30.” But it’s hard to cook up a story where someone would actually say that, so my first impression is just that the sentence is a bad one. It seems to me that in order for the sentence to mean “We met, and the time of our meeting was 10:30,” it would need to be “We met at about 10:30.” But I’m suprised to discover over at Language Log that a lot of people think “We met at about 10:30” is bad and that the “at” should be omitted! To me, without “at,” the sentence barely even makes sense!
Also FTR: “We met about four years ago” seems fine to me, and “We met at about four years ago” would be wrong.