There isn't a Scott listing for a "634a", just a "634". There is a listing for a "634A" but that would have to be a Type II. It's not a "Long Ear" or a "Smiling George". But it is a Type I. So the 11x10 1/2 would put it in the "634" family. If it is a booklet pane, it is a "634d". I don't think there are perfs on the left, so it looks like a "634d". If there
are perfs on the left, it is a "634" with the margin removed.
Two heads are better than one. Wait for another post in case there's someone smarter than me.

-IBFS