Thank you so much! this is very helpful.
I discovered that the Naturalization index cards (which I found on Ancestry) show the C-File number, so for those people I wouldn't need to request an index search, (which i think is done primarily to find if there is a C- file ). For several ancestors i'd like to have copies of their naturalization certificates (which I assume are in the C-files), so first I have to request an index search and then request a copy of the C-file . For pre-1906 naturalizations, I think the documents are with the court at which the naturalization was processed; some courts sent copies to INS>USCIS but others did not.
I also learned that for the post-1906 naturalizations the Petition for Naturalizatin and the grant of naturalization are on the same document; the Petition is on the front of the page and the Naturalization on the back. Are there also separate certificates of Naturalization?
FINKELSTEIN, BOOKSTEIN, KOENIG/SUKOENIG, LUSMAN, GOLDINER, SAGORODER/ZAGORODER (Radziwillow, Belarus/Ukraine; Ostrog, Poland/Belarus; Warsaw, Poland; Wolinsky, Russia/Ukraine)
LISS / ALPER (Motol, Russia/Belarus)
LEAF / LIFSCHITZ ( Rechitsa, Belarus)