See the changes noted on the first Ravelry page
"09/30/10 - Note for the chart page. The symbol key shows an empty box with “k on the RS, p on the WS” text next to it. This should be an empty box with “k” after it. All the empty boxes in chart are knit stitches. The only place to purl is for the center panel, between the stitch markers (odd rows only)."
The edge sts look like garter st so they would certainly be kept in knit throughout. The center panel looks like stockinette so knit on the front, purl on the back.