The years don't seem to correlate. The brothers I'm looking for would have been born somewhere between 1850 and 1860. If your g-grandfather was born in 1921, it might have worked, but your ancestors all seem to be born way before my g-g-grandfather (1854).
Thank you so much for trying to help, though! I treasure any and every clue I can find...there are way too many Kaczmareks in Poland. It's like looking for a needle in a haystack!!