Hello Peter,

You should contact the Macedonian archives/opstina for this question. The records of 1921 are most likely still at the city hall of Prilep, so I would suggest you write/call them.

Since during that time Prilep is part of the kingdom of Serbians, Croatians and Slovenes, most probably the surname would be recorded in a serbian version, Vailijevic or similar.

Could be possible. Do you happen to know if that is/was a common practise in those day's?

Apparently it was - check out the surnames * HRISTOV  from Monastir (Bitola) before and after 1918. : ( From *HRISTO to *HRISTOVITZ)

http://www.jewishgen.org/databases/EIDB/engine/gold.php?uid=13386512111931338651220988&referrer=httpstevemorse.orgellis2ellisgold.html&mode=running&time=1338658581642&arrivalPort=ellisgold&firstkind=close&FNM=&kind=close&LNM=Hristo&companionkind=close&CNM=&townkind=close&town=&SHP=&prtkind=close&PRT=&SYR=1905&EYR=1915&MONTH=&DAY=&SAGE=&EAGE=&offset=1&MRTL=&BSYR=&BEYR=&pagesize=50&CGD=&FLD=name&FLD=yoa&FLD=age&FLD=passrec&FLD=town&FLD=tmanifest&FLD=smanifest&FLD=yob&FLD=image&FLD=annotations&SRT=name&DIRECTION=asc

http://www.jewishgen.org/databases/EIDB/engine/gold.php?uid=13386512111931338651220988&referrer=httpstevemorse.orgellis2ellisgold.html&mode=running&time=1338658467791&arrivalPort=ellisgold&firstkind=close&FNM=&kind=close&LNM=Hristov&companionkind=close&CNM=&townkind=close&town=&SHP=&prtkind=close&PRT=&SYR=&EYR=&MONTH=&DAY=&SAGE=&EAGE=&offset=1&MRTL=&BSYR=&BEYR=&pagesize=50&CGD=&FLD=name&FLD=yoa&FLD=age&FLD=passrec&FLD=town&FLD=tmanifest&FLD=smanifest&FLD=yob&FLD=image&FLD=annotations&SRT=name&DIRECTION=asc