These parts are one of two types:
Exact using the license and or original dies to replace parts that
have been discontinued by the original manufacturers.
Not all reproductions are exact. not all are licensed. This does not
mean that they are inferior it does mean that a slight spec change was
made to appear to be exact..but technically they are not.
These parts are what is most readily available at this time.
Just because of company size, years in business and exclusiveness does
not necessarily mean a better product..
This is determined by experience...
installing and seeing the life and or fit...