Yep, know it is difficult to see, still curious about what is correct as I'm completely disassembling to the point of removing the mount bracket from body to re dichromate them and figure if I'm doing that getting the bracket right would be good. As it sits around the prop valve it can be seen when installed if you are looking there. The did look to be bare, and assumed S2 for the bolt, but figured I'd confirm before reassembly...
Thanks for the input.