Happy to report that this works as planned.
There probably is an idler pulley out there that is a direct replacement for ours with no bushings or spacer needed. For some reason they wouldn't let me go through the shelves at the parts store and open every box to find one.
When your pulley goes bad it will eventually sieze as mine did, and throw the belt. You won't get stuck, the engine will still run, just stock power.
As it looks like there is some need/interest in this, I will make up a few for those that need. I'm planning on only making 1 run of this, so if you want one tag up and say so. Materials, labor, and US postage, I think $40 will cover me. You will buy your own replacement pulley.
I'm going to let this sit a couple weeks untill anyone who wants chimes in, then run them all at once.
John C.