Tim,
If I can... I wire brushed that spot before, and put my camera up close since my eyesight isn't so great...(age) No luck.
So next, I put a piece of paper over it with pencil in hand to try to get an image but no luck still. I'll try again, if I have to stand on my head in the engine compartment. That wouldn't be a prettry picture!
I'm hoping the casting number will do it for me.
Jerry