Newbie help with VBB/ 150 Engine build

I'm new here, first post, first scooter too actually. I have a 64' Vespa with a 150 engine, VBB2M. It came dismantled, the guy said it needed a new kickstart and a some odds and ends. I took some pictures of a few questionable parts on the motor, before dumping money into it I want to make sure I go in the right direction.

This is a picture of the engine housing where the crankshaft goes, there is some fairly deep scoring on the engine block crank area.



The piston has a little wear, one little score mark, not sure if it should be replaced.





Hi, not sure about older vespas! but...if that gauge goes through the inlet pad(where the carb fits, raised section on the inside) as this needs to be good

as for the piston, it will work fine! but check ring gap! may be old?

ps top picture, were is the oilseal? is there a groove for circlip?