That mechanism on the camshaft/timing gear is the decompressor. It looks good in the pictures. The rod bearing looks as if it has been assembled with dirt/swarf either in the bearing journal or in the oil hole in the rod, but there are other possibilities, such as inadequate oiling of the journal before assembly.

You have the cast iron oil ring that was used on most GXV120s. It is not too badly worn. Here is the oil ring from one of my GXV120s:
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That is what an atrociously worn cast iron oil ring looks like. It had a gap of 0.142" or 3.6 mm. It used 3 mm of oil, measured on the dipstick, in about 1 minute from a cold start. By then it had oiled the freshly cleaned spark plug, and stopped running. My whole street was smogged out.

Some contractors get the very last out of their Hondas before they scrap them. Yours does not seem to have done a whole lot of work.