Is there a specific meaning for the double row of buttons? That is, is there still 33?
No special number of buttons. Just variations in style. The thirty-three buttons thing is a myth. One would have to be very tall to have that many.
Sorry, but 33 buttons are on my cassock, and I am 6'2"
There are common variations in the cassock (ie Anglican, Polish, Ambrosian, etc.).