Jeff, a promise is due :
Hi all,
I present you one 16660 with circled index dial.
The 16660 is a reference which I always liked, both civilian version that comex release, my favorite version is matte dial.
The dial is produced by Beyeler, Thanks Marcello Pisani 
In fact there has been (a As in 16800), as well as painted dials circled dials.
Quick reminder for the triple six reference:
The first (3000 to 3099) were all born with painted dials and the dials have been replaced by those circled with small logo.
The second (3100 to 3199) were all born with circled dials and small logo..
This is one of the 16660 'cercled' batch, I present to you today.
Just to see the difference between the first serie case back:
Credit Marcello Pisani
And the 2nd serie:
A wrist shot, note the stardust dial
(produced by Lemrich)
One last little picture to illustrate this post, and to salute those divers who worked with their Comex Rolex wrist, all at the peril of their lives.
Thank you for reading, and thank you to my friend Chris (Bajkal) and to Marcello Pisani always available and managed to stay humble.
"Grazie di esistere!"