I have found some links on familysearch.org which are not included on your list, so maybe you haven't seen them. Whether they contain anything not covered in your other links I don't know.
I can understand your confusion about whether he was born in Russia or Poland as one of the links specifies birthplace as being Kovno, Poland, Russia.
Kovno refers to Kaunas, a Lithuanian city, which at the time of your great grandfather's birth, was under Russian rule, if that is indeed where he was born.
born in Russia on April 30th,
I have 2 dates from the links, the 8th and 10th of April:-
according to the 1940 census, Michael had another wife
Yes, I found that one too:-
Talk about family dirt!)
I'm sure most peoples family histories rake up a few skeletons, there are worse things than bigamy ;)
Michal Prenewicz (alternative spelling)
Departed when he was 23 years old - 17 Oct 1900 - single
That would put his birth date well before that of 1899/1890 if that is the same person. About 1877 in fact.
Anyway, hopefully others here will have a few suggestions, good luck with finding any new info!