The simple (not compounded by other elements) hoea glyphs in the Tahua text are 10, only 2 on side a and the rest on side b:
 

red for side a

2

Aa8-14

Aa8-33

8

Ab4-68

Ab4-69

Ab5-49

Ab5-59

Ab5-61

black for side b

Ab6-4

Ab6-11

Ab8-29

Obviously the 2 on side a are different from those on side b. Among the differences observed one is the orientation of the bottom half: on side a the opening at the bottom end is towards right, whereas on side b the opening is towards left.

One glyph is though reversed, viz. Ab4-69.