147 any book is a sefer.
Where do you draw the line t seforim to the best of my knowledge seforin have been written in 2015 too?
Leib is mentioned in seforim though not in tenach/mishna/gemara.
What year heralded the closing of Jewish names in your opinion and why then
Also nobody in tenach/mishna/gemara had the names chaim, pesach ,yomtov ilan etc. Are these then not jewish names?