Mark,
I bought mine from Joe's Antique Auto in MA.
www.joesantiqueauto.com
(508) 278-3980 Good guy to deal with and shipping is fast and reasonable. I cut a slit in the old gear and knocked if off with a punch. I put the flywheel in the freezer and heated the ring gear on the barbie to warm it up and it slid on the flywheel no problem. Just make sure you install it with the teeth bevels going the right direction.