Your parts are from a cutoff saw version of a Homelite 360. Xl 400 would look just like a xl 12/super xl, but with a bigger bore and decompression valve on cylinder.
Oh wow. Yeah it was thrown in with quite a few builder saws I bought from a fella along with a ton of stihl and husky plastics. Should I change the title to homelHom cut off saw parts?