I agree with all you stated with the exception of the exhaust. When I saw the right side 3/4 front picture, I was reminded of the CB400-four's serpentine 4 into 1 exhaust. That was one of Honda's works of art!
That being said, a good old fashioned 4 into 4 wouldn't be bad either, but it's got to have the old style tank and seat combo to look right.