To compare the mss on J 1:18 see Schuessler's list here:
http://www.k-schuessler.com/john/Joh,%20sa%20505-508,561%201.pdf
Go down to the first section on J 1:18.
Here are the ids of the mss in the order he lists them.
600 AD Chester Beatty A used in Sahidica
600 AD Chester Beatty B used in Sahidica
9th C. see Schuessler Not used in Sahidica
9th C. see Schuessler Not used in Sahidica
5th AD PPalau Rib. 183 Main basis in Sahidica
PMorgan 569 [7th/8th] not in Schuessler's list was also used in Sahidica.
Regards,
Joseph