Old Polish (geoffreycaveney's theory)

[geoffreycaveney]

Geoffrey, thanks for the link to the dictionary. 
I didn't know you were a linguist, so I'm in a no position to judge your results. However I notice in the first word, for example, you invert the consonants and add a vowel, without giving the details if there are other possibilities  with the same consonants and other vowels. I admit that if you allow me to invert the consonants, I should read the word "pdzo" rather like поздъ or поздѣ - late.

I must point out that I retain the final vowel sound "o" as it appears in my reading, as the Polish nasalized vowel "ą" is actually pronounced as a nasalized "o" sound. So, if you want to match this with your idea, you would need to find a Slavic form meaning 'late' that is either written or pronounced "pozdo". I am not aware of any such form that has lost the "n" in "pozdno" but retains the final "o". 

Nevertheless, it is true that with a writing system such as this one--or Old Polish, for that matter--there will be potential ambiguities where it is possible to interpret a written word in multiple ways. The question then is, if you want to read this word in an alternate way, can you read and interpret the entire line in a way that makes sense with this other interpretation of the word? To take your example, if we simply substitute "pozdV" for "pizdą" in this line, it does not make nearly as much logical sense, given the other words in the line. Furthermore, Polish itself does not have such a form meaning 'late' with the "d" but without the "n"--rather, the Polish form is "późno". Czech does have the form "pozdě", albeit with the wrong vowel at the end. But even if we set this aside, we would then need to produce a logical and sensible Czech reading and interpretation of the entire line with this word. I very much doubt that it is possible to do so.