Have you looked at any of Paul Robson's stuff? He was going to do a retrochallenge on the Watchman a couple of years ago, and he's got 20 blog posts, some info and some code:http://watchdev.blogspot.com/
I figured that SM510 was the name marketing used and CMS54C was what the designers used. Top Gun's top metal says CMS54C (actually, the first C looks more like a [, and the S is under the CM) and underneath it looks like it says KMS598.
Likewise, TMNT (assumed SM511 from ROM and RAM sizes and melody ROM) says
KMS 73B and KMS 774.
The G&W die shot says CMS54C over CMS565. I'm guessing the numbers 598 and 565 are the ROM IDs; they are repeated in a different location on the 2 dies.