You're very confused, or purposely obfuscating. You're conflating Israel scattered and Israel gathered. Israel is what we call the descendants of Jacob. They are Israel's descendants. This issue here is their national statehood.
Either you're denying Israel was ever scattered or perhaps denying they were gathered in 1948? Hopefully you're not saying that.
But I guarantee you Peter wasn't denying Israel had been scattered and lost their o9sovereignty and statehood.
Not to mention that Peter in Acts 3 refers to all the house of Israel as "men and brethren," a common use of that among various people, back then.
In Peter's case, because they were fellow Israelites.
It is not always a reference to fellow Believers...
Luke 21:16 And ye shall be betrayed both by parents, and brethren, and kinsfolks, and friends; and some of you shall they cause to be put to death.
There it refers to kinfolk and friends.
Acts 1:16 Men and brethren, this scripture must needs have been fulfilled, which the Holy Ghost by the mouth of David spake before concerning Judas, which was guide to them that took Jesus.
What, are they already saved?
Acts 2:29 Men and brethren, let me freely speak unto you of the patriarch David, that he is both dead and buried, and his sepulchre is with us unto this day.
Again, the same question.
Acts 2:37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?
What are they already saved?
Acts 3:17 And now, brethren, I wot that through ignorance ye did it, as did also your rulers.
Again, the same question.
But Biblewriter has already exposed the very basis of the guy's many errors...
Edward Irving;s Historicism