Snowbeard,
Well, I've replaced the inserts on a grand total of one chain wheel. However, I have not heard from anyone else that they made their own inserts (let the contradictions begin). In taking the old ones out and putting my home-made ones in, they were well fit and not loose in both cases, and my clutch appears to work perfectly, my limited exerience with other bikes notwithstanding.
By the way, nice video.
Richard L.
P.S. I asked in a previous email where you got your mufflers, do you mind sharing that info?