Deductions & credits

Wow, now this sounds too good to be true!  Effectively, two #3 stimulus checks into the family for him. Of course because he was a student and dependent, he didn't get either of the first ones, so maybe it evens out.  I think we misplaced the Letter 6475's but we both created IRS accounts and checked what it said, and that matches up with what we received, so can we just go with that?  (the $4200)?   Thank you so much for your great and very speedy reply!