Thanks for looking and for the compliments everyone.
Hammish, you're probably right about the typical fate of thin ringed bows. Some of it might have to do with the individual piece of wood and how strong it is. Some of it might have to do with the tiller and the way the back has been worked. I took every precaution I could, but I know it's pushing the safety limits, so needless to say this will not be my go-to shooter. On the other hand, my confidence went way up on working with more reasonable thin ringed staves in the future (1/16"-1/32" for example).