Hi Ryan,
From my experience that clutch will be scrap alloy and nothing better. It's age is against it and how long the cotter was loose and then pulled apart and discarded as they don't just fall out, along with the tell tale signs in the rail tells me that you will have no other choice but to replace it. Also you told me that when you removed it there was a bit of free play in it on the shaft is enough not to consider it any longer as there should be basically none, a clean slide on fit only.
The particular version of the clutch you have there would have to have been the most troublesome for Scott Bonnar, but it certainly kept the cash registers ringing over and over again.
I've inspected the close up photos of the drive train behind the chain case and all seems rather in order there so there's not going to be a hellva lot of cash that's required to spend on it apart from a spin grind of the reel along with new bearings on each end and a new bed knife fitted.
Cheers,
BB.
PS. Yes the new style sloper engine from Briggs are most definitely a smoother running engine, along with the Honda's and Chonda's.
