Broken down old family lawn mower left and forgotten trying to bring it back to life used WD-40 to get rusted bolts unstuck and unceased

Fixing it up as I speak getting new parts for it the white part on its back with exhaust cover has already been redone also use w40 use to drill out a broken stud and to put new threads in it also has a severe rusted chain that I'm going to be using WD-40 on to get it back to working order