Not sure if you´ve had any luck over the past years with your siblings. I am from Venezuela and hope these tips can help: 1) If your grandmother´s father was Isaac Gonzalez, then her last names should read "Gonzalez Garcia", because for all legal records, the first last name to appear is your father´s, then your mother´s (maiden) last name. If in 1945 she was an adult, she has a "cedula de identidad", which is a legal ID with a unique number, as unique as a US Soccial Security Number. Her husband also. In Venezuela you are issued a "cedula" when very young and it is the most important personal ID document for us (at current times, you are required to have a cedula issued around the age of 9-10 years old and elementary schools may not enroll your child until he has obtained one!). Even if she has not been in venezuela since 1945, if she has a cedula number, log on to http://www.cne.gob.ve/web/index.php
and where you read "consulte sus dadtos", use that number to read the exact name that is registered for that cedula, and that´s the name you should be looking for. The capital "V" stands for cedulas issues for a Venezuelan national (this would be her case if she was born here in Venezuela, as "E" cedulas are issued for foreigners. That website has names of everyone who has a cedula, even if your over 100 years old..! Are you sure her middle name is "Del lo regis"?? Doesn´t sound like any Spanish name...check the spelling..also you mention Isaac Gonzales as her father...GonzaLEZ (ending in EZ) is of Spanish origin, whereas Gonzales may be misspelled (??) or suggest Portuguese origin (Goncalvez is also Portuguese). Ines is a much more common (and correct) form than INEZ as you spell it. Tia Dora Garcia...are you sure it´s not Teodora Garcia? Tia Dora means "Aunt Dora"...check spelling again.
let me know how things go and hopefully you have reconnected!