New analysis of f116v, Central Bavarian dialect

[monisusa]

There is simply no historical evidence that a “c” is an abbreviation for the word “Zeh.” If you know of any, you'll have to provide evidence for it here.

I also haven't found any evidence that the word “Zeh” was ever written with a “c,” i.e., “ceh.” Moreover, a single “c” would have been interpreted at the time as a Latin abbreviation.

While “c” (tse) sounds similar to “zeh,” “ceh” would be extremely atypical.

Do you have at least one instance where “Zeh” was written as “ceh”???

Hello, I think it is not always effective to search for "attestations". Late medieval spelling was highly individual and irregular, particularly if the author was writing in a language foreign to him.
It was ONE scribe who decided to spell ONE word in his own special way. It is not representative of the whole period nor of all regions, scribes or scriptoria.
The ingredients of the ointments are typical for painful joint inflammation which could affect a toe, a gout toe (ein Gichtzeh).
Which logical transcription for "c" would you suggest for these parts where the "Zeh" appears? And does it also make sense with the whole context or is it just a single
word without any connection to the content? That's what we should ask ourselves. 
Kind regards, Monika