My name is Rollie Stamps, email curtstamps@...
You and I are in the same situation. I am an American, raised as a Christian, but also felt an affinity towards the Jewish people. Neither side of my family knew anything about our ancestors past about 4 generations ago. I worked with several DNA companies with a varied degree of success as the first failed to report my last generation and the second did. My ancestors were Jews and I didn't know anything about them. I have since worked hard to make a family tree for both sides of my family and have been very successful with the information. Once I started getting names, I bounced them off of the database for JewishGen.org to verify if their names were on record. I was very impressed with the findings. A word of caution, however, when using databases, I have noticed some minor errors, so always try to use more than one data base and show credit for the information you get. That will allow you to find the information in the future and also prove your relationship to them when needed. Also, get your DNA tested. That way your findings can't be argued. Autosomal DNA testing gives you the ethnic groups of both sides of your family, but only going back about 4 to 6 generations, so about 150 years give or take. Women can have their female lineage tested using mtDNA. This is only for women and tests the womens side only (Daughter-Mother, etc.). For men, the test is yDNA. It tests only the males side (Son-Father, etc.).
I was thinking about your statement "does a name prove jewish ancestry"? I believe it can, if you also use available scientific testing with your trees. In addition, verify the names are not sound a-likes. Not all people with the same last name are related. For that matter, not all names that people think are Jewish sounding are in fact from a Jewish family. The fact that you can connect yourself to another person through lineage with DNA and/or use of one or more databases or printed media is likely sufficient, depending on the sources you use. What you might be asking is whether or not this connection makes you a "Jew". If that is your question, than no it does not. I have spoken to a few rabbis and understand this better than I did when I started looking. I am not qualified to go deeper into that explanation other than this, if you are like me, a Christian, than we do not worship through Judaism and are not considered to be Jews. I believe the term for us is "seed of Israel", if you indeed are of Jewish lineage. Personally, I take pride in my Jewish heritage and support Israel. My parents raised me this way.
You asked about Catholic registers. I am not Catholic, but have been able to connect the dots on our history and a possible explanation why our ancestors stopped worshiping as Jews. Persecution by the Catholic church, called "pogroms". I have found several members of my tree were listed as Catholic clergy with an assortment of positions, but none the less counted as Jews. One was even Sainted in Belgium as a Beer maker. As Europe became less friendly to the Jewish population, it appears more immigrated here to the United States. I think it is amazing the lengths that people will go to in order to save their lives and that of their families. In the cases of my Catholic relations, I can only presume they were either hiding deep or their family had stopped worshiping through Judaism so long ago that they didn't realize their own heritage. I personally believe it was both.
If you have not had your DNA tested, try MyHeritage.com for your autosomal test.I do not work for them, but they were the second DNA company that tested me. They have their own data and are based in Israel. In addition, they show their test results down to 1% of ethnic rendering unlike the others. If you still don't find anything but don't want to give up, don't. You might find it after all. I hope this helped and let me know if you need any clarification.