Rolex 1675 Green Fat Font

I have seen green GMT inserts before, usually in smaller font and evenly aligned. The green inserts are thought to have been prototypes delivered to certain dealers which in turn made their way into the gray market. Most of these prototypes or rare colored inserts (think blueberry) have small notches on the backside as a differentiating insignia, but not all do.

I can't comment on this particular one, other than it's something I haven't seen before. Many of the clues as pointed out are cause for caution. I commend the OP for pulling the FS post.

There are lot of high quality aftermarket replicas being produced. For example, today I was shown a Redback COKE insert belonging to a 16710. Again, another variant never seen before in the collector community causing alarm.

It's getting tougher out there in finding original examples. Hand written Rolex Warranty papers are being peddled on forums with a 100% premium (worth less than toilette paper, in my opinion, see OF FS section) cases are being spot welded and reproduced in Italy to perfection and inserts have long been on the watch out list.

All this makes vintage collecting more challenging and ultra sensitive to anomalies.

Good luck.

-A