See.. this is actually something I'm not 100% sure about. I know in the US Kazimierz was buried in a Roman Catholic church. But where he lived in NY, the Rusyn population wasn't large from my understanding and I'm not sure if there was a Greek Catholic church. One of those – did he choose ot be buried in the Roman Catholic church because it was closer to Greek Catholic than a Protestant church, or was he actually Roman Catholic. My my aunts, uncles, and dad were raised in the Episcopalian church. But I think that might have been because of my grandmother. I'm not sure what my deda was raised as.
Greek Catholic and Roman Catholic are same Church. Well it not proves much if he was burried in RC graveyard. Thing is that major Archibishop of US in end of 19th century was strongly aginst Eastern rite Catholics, John Ireland. Some of them re-joined Eastern Orthodox Church because of his insolence (Rusyns were originaly Eastern Orthodox before 1648).
If we knew he was Greek Catholic, we could determine that he was Rusyn, in this way, situation remains complicated.