If I have thought correctly in cutting and pasting the three glyphs at the beginning of line a7 into the form of my perceived structure, then we maybe should compare:

Aa7-1 (501)	Aa7-38	Aa7-59 (501 + 58)
1	4	6

Here the pair at right evidently should be viewed together. Furthermore I believe their peculiar heads can be explained as hau (GD19), i.e. completely opposite to the bald head in Aa7-1.

Please note that we have this sign in Aa7-58 too.

And then we can use earlier information about the variant circular hau in connection with honu.