Now you know why I had so much hassle trying to fit an alloy ST4s swingarm to my ST2.
It was pretty clear to me that from where the pinch bolt holes were located in the swingarm that the 'pinch bolts' would have to be some sort of cotter pin - because the pinch bolt holes intersected the swingarm pivot hole, so the bolts would have to have a flat on them.
Trouble is that the swingarm I got off eBay came without the swingarm pivot and without the cotter pins. The pivot was OK - exactly the same part number as my ST2 - but the cotter pins
I had them on back order with both Nelly and JHP for nearly a year and they still couldn't get them. Now you know that both Nelly and JHP can usually pull rabbits out of hats when it comes to parts so it wasn't their fault - the damn things are just nigh on unobtainable.
In my case I just gave up and left the original swinger on.
The moral is...DON'T THROW THE OLD COTTER PINS AWAY.
PS: I suppose that if you've got a damaged one that got mullered taking it out, you've always got a pattern that you could get a local engineering shop to replicate, in my case I had no idea what size or shape they should've been apart from the sketch in the parts catalogue.