Tony - got 'er done today and your measurements were right on! I used 1" bar stock, nylon or Delrin I think - it's not polyurethane as I thought. The center hole was drilled using an "X" size bit - .405" as I recall - and the bolt fit perfectly. It's a huge improvement from the original, even before the bushings were damaged. I didn't notice any noise/vibration with the much more hard and rigid bushings I made.
Here are the bushings I made on our shop lathe - took about a half hour for both.
I can't thank you enough! Next time you're in Greece, beers are on me!
I'm able to use the shop lathe for very limited personal use... I'd probably get in trouble if I started a business out of thisit might be cool if you could make them for others. Might even be an opportunity for some profit.