Attentive followers of the Suśruta Project will recall the project publication that focussed on interpreting the writing of छ by early Nepalese scribes . Our project members are currently debating a similar issue about the letters श and स specifically in the handwriting of the scribe of MS Kathmandu NAK 1-1079 (siglum N). This manuscript has been dated to the twelfth or thirteenth century CE . Our question is, can we detect a difference in the scribe’s writing of these characters? Does he routinely distinguish them, but sometimes make errors? Or does he simply not distinguish them at all? Our team is currently divided on this issue.
Here is a chart of instances that we are discussing, kindly provided by Harshal Bhatt:

One of our reference points is the discussion of MS Kathmandu NAK 3-370, a palm-leaf manuscript datable to 1052 CE . On p. 60, Csaba Kiss noted the instability of the orthography of these characters:

The discussion continues …