Perth Mint Lunar III Series

[Pete]

Just received my new Perth Mint Lunar 2020 silver one ounce coin and added to my nice boxed set only to find it is seriously loose in the cut - out.

My bespoke Lunar wooden box contains the full series II, all nice and snug, but the 2020 coin is significantly smaller, so be warned.

I checked Bullion byPost for specs and they are incorrect so I resorted to APMEX.

The series II ( to 2019 ) coins are 45.60 diameter x 2.6 mm thick
The new series III starting with 2020 is 40.60 diameter x 3.21 mm thick

I don't wish to place the new coin and future coins in oversized capsules just to fit the slots but that would be an option.
I definitely want to avoid adding those black rings inside the cap because I am convinced that over long periods of time they cause early tarnishing.
 

[Gildeon]

Lunar III series will have their own boxes, probably nothing common with Lunar II. I think that more or less all sizes are different.

[johnnyhann]

new Lunar III 1oz is same diameter as all of their other standard 1oz silver coins (kook, kangaroo, etc). Perth Mint actually sell their own official presentation case for it so those would be perfect for the moment

[Shinus73]

It was the Lunar II series which were a non standard size for a 1 oz silver coin, significantly larger than anything else in the market. 
Series III is a return to the standard size and the same as Series I.