Having covered AOV and GA there aren’t a lot of Christmas songs that I haven’t covered so I can skip:
265 Joy to the World AOV 1/170
266 O Little Town of Bethlehem GA 296
267 O Come, All Ye faithful AOV 1/167
268 Of the Father’s Love Begotten
269 Once in Royal David’s City GA 297
270 Silent Night, Holy Night! AOV 1/168
271 Sing We, Sing We Noel AOV 2/124
This hymn was written by John Morrison (c18) and the CWB II has adapted lyrics by Jubilate, available here. Hymnary can take you through the various other iterations of the text.
The tune is DUNDEE from the Scottish Psalter (c17), harmonised by Thomas Ravencroft. Some versions shorten some of the long notes but this is the tune as in CWB II, and it sounds more Presbyterian this way. I got the chords from versions on Hymnary.