I'm pleased to report that thanks to a few tips, we've got 103 of the 104 Sunday POGO pages we need for the next book (three of them include black and white panels from book reprints that we've colored to match the surrounding strips, but that's just between you and us).
The August 19, 1951 strip remains the problem child — or "chile," as one of Kelly's characters might say. We have a 1/3 Sunday page tearsheet, and have been able to track down two of the three panels from the missing top strip as this sequence appears in a book, but the opening panel is nowhere to be found. If push comes to shove, we'll print it this way with a little note explaining to fans that we haven't been able to locate this strip (and will publish a full version in a later book if and when it turns up) — we did that with a PEANUTS strip back when, and it did eventually turn up.
(click image to enlarge)