I recon your clutch problem is due to the worn thrust pad not the housing or the clutch itself.
Your clutch to me still looks servicable maybe using nyloc nuts & bolts instead of screws if the thread is damaged as the clutch housing just clamps together.
The cotter pin must be used on older scott bonners the spare parts clutch housing seems to use set screws aswell, your engine doesm't have the ground flat on the output shaft for a cotter pin, it has a keyway
I would try the bolts and purchase a thrust pad only, your cork clutch lining looks fine.
