1965 Buick Super Wildcat Convertible Header Bow Issue

I just bought this car and I am new to the Buick world. I need a new header bow for the convertible top and have run into the early or later header bow. What is the difference? And is there pictures available. Please help.
Kip Johnson

 

Kip- I sort of know what you are asking about. I can look at and get pictures next week.

 

I found out the early header bow is cast steel and the later bow is stamped steel. Thanks for the help.
New question Body frame is there a difference between the convertible and the 4 door body frame.

 

The only difference I found was the holes for cross braces were not drilled.
I may have missed something but it looked like a match.