Evidence suggests the 16 glyphs from number 77 (Ga4-1) could be referring to the end and new beginning of a cycle dictated by Moon:

Ca4-4	Ca4-5	Ca4-6
Ca4-7	Ca4-8	Ca4-9

Ca4-10	Ca4-11	Ca4-12	Ca4-13	Ca4-14	Ca4-15	Ca4-16 (92)

The pair of moko glyphs would then be a pair because Moon has 2 faces. There are 2 'Janus hau tea' glyphs, there are 2 rau hei (excluding the composition in Ca4-4), and there are 2 ihe tau (excluding the composition in Ca4-5).

Beyond these 20 glyphs, which presumably are referring to Moon, there is also a single moko in a position which may represent winter solstice:

end of Old Sun	4 black nights				birth of New Sun
Ca4-20	Ca4-21	Ca4-22	Ca4-23	Ca4-24	Ca4-25 (101)

This single moko has Sun signs:

Moon		Sun
Ca4-5	Ca4-11	Ca4-23

Not only is there a hint of a male member at bottom but we can also see that his mouth is open, as if in anticipation of spring ahead, the time of vaha mea.

The location of these 3 moko glyphs early on the front side of side a can therefore be explained as due to the back side stretching its influence on to the first 4 glyph lines on side a. We can still think of moko as a sign belonging late in the cycles.