Home alone.

pic one. the cluch exposed, there was a bit of ding in one of the plates, but it's all working so I'm reluctant to fudge with it.
Pic two.  the seedy underbelly, to me it all looks ok, it's 40 years old, give it a break. my belly has a few dings too.
Pic three. There is a few interesting bits here, mainly the circular indentations near the breather?? WTF. why?