So Israel...was blinded in unbelief...until such time as Israel saw and believed...at which point Israel...would be unblinded...
No.
The Jews were blinded in part, but a remnant believed.
That remnant of Jewish believers then became one new man with the Gentiles, who were made up of pagan Gentiles and descendants of the 10 tribes from the House of Israel Gentiles.
That's how all 12 tribes (all of Israel) was saved.
That's how the stick of Judah was joined with the stick of Joseph.
That's how the NC was made with the House of Israel and the House of Judah.
Because the 10 tribes had been divorced, they could not remarry until their first husband died.
That's why the gospel of Christ didn't go to the Gentiles until after the cross. It would have been an abomination beforehand (Deut 24:4)
"the fulness of the Gentiles" happened in the first century.