Stuck on my 2nd great grandfather

Hi, I'm new to CGSI (just joined) because I've heard that it may be able to help me get through the roadblock on my family tree that I've been trying to work through for about 10 years. Family records were burned (inadvertently) so most of what I have is through asking my family members and my own research. Hopefully having more understanding how Slovak names (first and last) were possibly originally spelled would help. 

So, the last name I'm stuck on is Chincharick. My great grandfather, David spelled it that way. However, I was told by his baby sister that some of his siblings (he's one of 11) also spelled it Chencharick. I've also seen records dropping the 'c' entirely (Chincharik/Chencharik.) His father, Mike, has it spelled Chanchark on his death certificate.

I know this is a case where when my great grandparents immigrated somehow the spelling changed, but I can't find any records at all. The earliest record I have is my great grandfathers birth certificate from 1923 and his fathers death certificate from 1947. Hopefully if I can crack the code with the spelling I can start looking at church or census records from Slovakia.

Can anyone with a better knowledge of how names were spelled help me out? Thinking if the last name was changed to be spelled phonetically, would there be any alternate spellings I could be missing?