wanted: clutch arm pin.

Matt,
That's called a 'bucking bar' and you can make your own using a 5/16" drill bit. Use the shank end of the bit. You can cut it with a Dremel and a cut-off wheel. The length is sort of critical so you might have to experiment a little but if you make it so it protrudes from the center of the sprocket at least 1/4" you'll be in the ball park. Don't forget there's also a ball bearing behind that pin. After you get the length right smooth and polish the ends of the pin and lubricate it, the ball bearing and the clutch actuator cam with a good grade of heavy bearing grease.

Maybe someone else will chime in with an accurate measurement for the length.

Tom