Is that an Energy Suspensions urethane sway bar end link kit? Or is that a urethane body mount for a passenger car? Can't really tell the size from the pic, no reference. Or am I crazy? Are you looking for a bushing to fill in the gap between the bolt and the urethane bushing?
The first 2 things that come to mind are:
1. (cheap) look for a length of pipe with 3/4" i.d., and keep your fingers crossed for the right wall thickness to end up at your 15/16" o.d., may be tricky, if memory serves 3/4" i.d. black pipe is approx. 1" o.d.. Is there any chance you can open up the hole in the bushing a little so a piece of pipe would work?
2. (expensive) have your machine shop take 15/16" bar stock and bore out the i.d., but that is gonna cost a ton.
It seems to me I have seen the rubber cab mounts for older pickup trucks with the steel bushing built into the bushing itself instead of a separate piece. If you can find those it may actually be cheaper to switch than muck around having stuff machined to order.
Here is the Energy Suspension online catalog:
page 12 had universal mounts and isolators and all the dimensions are in a nice chart.