Is having the check number on the reverse the aame as theplate number on the front rare and is it worth anymore then face value or just too common
Nope, two entirely different things. The number on the reverse is the back plate number. Welcome to CT.
What if you have a complete strap, all nice crisp bills, that is in sequence, and the last digit are all off?
That would be nice but it’s still a minor misprint called a stuck digit. To have a complete strap doesn’t really add much value as it’s a minor error. Welcome to CT.