The bike is 2012 SE and has been rollerized and valve checked as of late last season as part the 10k. Have put about 3300kms on her since.
I'll get a closer look today and check it again during / after a ride. I would imagine the coated surface above the screw that I highlighted in red is susceptible to the type of wear and breakdown on all our bikes.. It's not too bad and am probably just being anal.