These spools are all customized by Simon Shimomura at Fishy Business.
They are made exclusively for 4500~6500 size reels made during 1972~1980.
These spools will not fit CA, CA, AL, and other models. Be sure what your reel is before purchasing my spools.
*** 4500C fits 4600C, 5500C fits 5600C, 6500C fits 6600C models.
You can enjoy smooth longer casting than the original spools as accurately and shaft is nicely polished.
My spools are made strong and you will have no problems to use tough bladed line. I wonder if you had some issues using bladed lines on the classic Ambassadeur reels particularly on 4500C, and 5500C model spools.  
*Factory second item: They are perfect functionally. Only the reason why I rated these items as factory second is the arbor (core part of the spool) came out slightly bumpy.

All made in USA. 

Simon Shimomura
Fishy Business