I like your ideas--if you just need to hold one diameter dowel. I actually
made mine to bridge the gap between my pin chuck max opening and the
minimum gripping diameter of the spigot chuck.

--
Gerald Ross
Cochran, GA

Or...just drill the hole size needed, on the lathe, turn the OD to a size
you can chuck on. Then saw through only one wall. Bushing will hold
together. Called a "split bushing"