The vowel exchange "a" to "o"

[Kaybo]

If you are looking for a more consistent exchange between two characters in the VMS then the answer is with t and k . Unlike the Italian examples that exchange at the end of a word for grammatical reasons, t and k in the VMS exchange mid-word, rarely at the end of a word. See the attached for frequencies of the exchanges. There is a general parity in the frequencies. Almost every exchange gives a valid VMS word.

Change of one letter in a word or extending a word by inserting a letter is an interesting phenomenon and I think it cant be explained by letter exchanges in Latin words, they exist but not in this frequency. I have not done any statistics, but most exchanges and additions are in the middle of a word. And the insert/addition is very rarely at the omega position. Its like g to 8g. One interesting insertion is the T(kt) between the cz (ch). 

This insertions and additions could fit into number system.