I think I found it...but there is a whole bunch of thick sludgy greasy crap on there ...I have to do an engine clean soon...so hopefully I should be able to get to it. What I scraped off didn't reveal anything...
there was a 'sticker' right beside that flat spot that started with an "L3" and then a bunch of numbers...what do you suppose that was?

What's "HM" by the way...sorry if that's a stupid question.

Jason