Garry,
Agree with the others.
The aftermarket ones do fine for a "driver" quality car.
For a really nicely preserved Authentic they are more of a no-go.
You _can_ see the differences once you have an original ring in your hands ...
Used ones are available. Just be patient. Dont' t pay the price some silly ebay-sellers demand...
:'(
I have been looking for these for > 20 years and have got plenty.
Some of these were less than $$ 10 each but would need proper rechroming in order to be perfect.
Basically .... your choice.
Good luck with your 230
Achim