Looks like an awesome project Clownie3!
Notice the difference between a XL350 and XL500 chain guard. An XL500 has an extrusion right where the clutch is similar to a TT500 where the XL350 chain guards are completely flat along the entire chain guard. Here are some pictures showing the difference.
XL500
XL350
View attachment 80861
Just wanted to clear that up so everyone knows exactly what they have and what they are looking for.