I am a first generation American born to a French father and a Polish mother, and I am working on getting the Guichard family tree from my dad... hopefully once this happens it will shed some light for some of the people that are hunting their heritage.
Although an old name (and yes, the family is predominantly catholic with large families) it is still not very common, even in France, so a lot of the Guichards that are left in France, I am related to.
I was born in America, my father and his siblings were born in Jargeau, France in the Loire valley, and as far as I know, his father was born and raised there as well, and his father before him had a farm there or near there. I do remember that when I was about 8 or 9 (about 14 years ago) I went to visit my father's cousins (I can find out where, I'm not sure right now) and one of them had the family tree in possession (at which time I was placed on it). This was a large group so I know there are more of them still there, but I'm not sure how many are left with the name. I know that as far as my grandfather's branch goes, I am the last with the name because my grandfather had five children, two boys, and both boys had girls (I am an only child, and the other four girls have disowned the family).
I'll try to post the tree as soon as I get it, but I hope maybe some of my story has helped.