Can we make isoglosses?

[Koen G]

I saw the faded line as a blemish on the parchment, where the ink of the left leg didn't "take". But it is true that we would expect a descender on the "h". With that being absent and there being some indication of a light stroke over the left leg, the case for "b" is probably better. 

If I read the 2D image correctly, there may be some elevation here in the parchment, which may have caused the final stroke of the "b" to travel further up and left than intended.