Ron, 
This cabinet came out perfectly, it's a beautiful piece of furniture & I'm positive the recipient will be thrilled with it.
As for your noticing the extremely slight difference in the disk's heights, believe me you are the only person who will ever notice this. It's only because of your eye as the designer - builder to be aware such a situation can or might exist, having gone through the details of construction.
Others will view it for what it is, a beautiful cabinet that was made with love for the craft, and sweat & tears in each operation that was involved.
Two thumbs up Ron, 👍👍