I understand that the vast majority of Jews deported from France by the Vichy regime were actually refugees from various countries (mostly Poland), as opposed to long time residents of France. This was as I understand used as the main excuse to create a fig-leaf of legality.
As to numbers, my 1909 Encyclopedia Britannica notes 49,000 French Jews outside Alsace-Lorraine in 1872, and 159,000 including those provinces. In 1933, with Alsace-Lorraine returned (and various population shuffles in that territory undergone after 1918), there were 150,000 Jews in France according to my "Grosser Atlas von Weltgeschichte" and various other sources seem to agree on this number (except Gilbert, who puts it at 225,000). These same sources seem to agree on 300,000 to 320,000 as the population in 1940 Various numbers exist for the number of deaths subsequent to deportation to Auschwitz, anywhere from 65,000 to 83,000 (you'd think they could be a little more precise on this), and 180,000 to 200,000 as the 1945 population, with that increasing to 235,000-250,000 in 1951.
As noted the population is now triple the post-war figure and double the 1951 figure.
During the same period of time, the population of France as a whole has only increased about 14% from 42 million in France and 2 million in Algeria and Tunisia to around 50 millions today, excluding Muslims. Its difficult to believe the French Jewish population increased naturally by a vastly different amount. Clearly, the vast majority of Jews in France are there because they or their parents chose to move there since 1945. France was hardly their only choice either, since they could have also gone to the US or Israel or Britain or any number of other countries.
Its difficult to see a tripling of a sub-population while the general population increases under 15% is anything but a "flocking" of outsiders to a tolerant, peaceful, and profitable locale, where people though they could live without fear and with opportunity.
Well...
One can quibble about terminology about how the numbers are arrived at, but many of the thousands of Jews who found themselves in France were using it as a "transit-point", not intending to stay. This combined with the US limiting immigration severly, forced Jews who were fleeing numerous tyranies to descend upon France. In between world wars I and II, Jews emigrated to avoid various progroms, attacks, hatreds and other assorted European horrors. This is hardly the flocking of Jews to a peaceful and tolerant society, but rather choosing the lesser of evils.
With the storm clouds of Hitler, the brutality of Stalin, and the crushing poverty (and Islamic hatreds) of the North Africans upon their necks, the age old hatreds of the French seemed paltry in exchange. Besides, America had closed its doors and there was no way to escape. So, yes in the turmoil of Europe of the 1920's and 30's, France was a destination for many Jews (to their cost.
However, considering the pre war Jewish populations of Germany, Russia, and Poland, the post war "thousands" that came to France were just that; thousands. In addition to that, considering the millions that ran to Israel from Europe and Arab countries after the war, the population of France (using your numbers) is hardly indicative of "flocking". France was one of a few western countries that allowed them in. Now the French, it seems, are very sorry they did and are doing their best to correct their "mistake".
How did the encyclopedias and almanacs arrive at these figures? Did the census forms contain a checkbox for religious affiliation? Did they go from door to door noting the presence of a mezuzah? Or did they knock on the door and say, "Pardonnez-moi, monsieur, etes-vous Juif ou Français?"
In other words, Hermann the Jew-Chaser, citizens of France who followed the Mosaic faith, CONSIDERED THEMSELVES FRENCH and would have said so on any survey or census form.
Certain people like to "quote" census figures from unavailable sources in order to make certain claims about the "actual" number of Holocaust victims.