If your going to restore it.Then check the parts are usable then start the painting process,but if your going to restore it,it is a far bigger job than just putting back together in a working order.I seen the video of it,it didn't look that bad just some adjusting and lubing,but now it's a much bigger job.So really you need to work out how far your going to go.Like when I restore a mower I pull it apart check every part and replace anything not usable.Work out whether it's a full restore (Most are)and then prepare each and every part paint etc etc.
So I guess you need to know how far you want to go.
That's the first thing you need to work out.
How far do you want to go?
As a build like this even on this forum is going to take time.
Do you want to restore ?
or Just put back together?
