I believe you'll find that Ringo used an 18" on his right and a 20" on the left.

In my opinion that 20" is right. That's considered thin for the period. And the 18" is right in the ballpark too.

Yes, as I said, the 20" is for the left side

cheers

He got his 20" in 1964 from Manny's in NYC. From the Beatles Gear book I can see that it has the characteristic dark unlathed lines in-between the regular lathing lines. That means his 20" was probably late 1950's, but at very earliest 1960's.

As for his 18" it could be anything between a 1947-1949 trans stamp, all the way up to the a mid 50's large stamp. But the reason I bring these things up is to let you know that if you want to be as authentic as possible, you would eventually want to try to get Zildjians of similar weight from similar eras. In other words, hand hammered A's.

I stand corrected...baby crawl2

Drumaholic that is genius. I am always looking for both an 18'' and 20'' to also be used with tribute acts.

I assume you are trying to emulate Ringo ,after he became famous, as in the post Ed Sullivan era?--------- There is a lot of evidence that some of the earlier recordings, in his Premier drum days and maybe even his Ajax days featured other cymbals. The 20" pictured with his Premier kit, looks to be an Ajax cymbal(Ajax have a unique profile) and he certainly used some Zyns too. If I listen carefully to I Want to Hold Your Hand and other early cuts, I can easily see that they might not be Zildjians.