When you're ready for the chuck portion, here's what I recently came up with. I went to my Home Depot and in the toilet parts section, found two similar black rubber parts, around $3 each. The photos show a quick idea with one of the two. The cut-out hole I created was sloppy but it worked well. The rubber is thick enough that it holds the completed reel seat solidly. I just need to mount the motor in the wood stand in a more rigid fashion, it wobbles just a bit. The aluminum shaft coupler was less than $4 on ebay. The new motor is about 12-15 rpm, much better for my style of applying thread finish than the original 6rpm motor.
I may change the design to have the motor mounted on the outside of the stand, the coupler running through the stand. and stain new uprights a nice color with satin varnish.
eric
fresno, ca.