First I’d like to say I love your site. The questions are often ones I’d have asked myself, and your answers are enlightening. You have really been a blessing in my expanded knowledge and understanding of the Bible. On another website there was an article concerning the number of Messanic Jews in Israel and the US. The numbers were 50,000 something in Israel and around 350,000 in the US
The 144,000 witnesses are only identified as coming from 12 named tribes. Neither their physical location nor their nationality is given, although I think most people assume they’re Jews from Israel. As for being from among the Messianic population of today, that’s impossible because true Messianic Jews are part of the Church (Gal.3:26-29) and as such will go in the Rapture. The 144,000 will not be chosen until after the Church is gone.