not locally atleast. You might find close, but chances are they will be a few mm's big or small, and will work temporarily, but if they are too big they will soon elongate and cause issues.
If you dont mind them being turned out of polyurathane, Im eager to try out my new lathe I bought, poly would be pretty rough and noisey though.
Aluminum or poly but it would have to be very tight, and be hydraulicly pressed in to prevent it from slipping out, and id still be worried about it sliding out, as there are no retainer on the housing to hold the bushing in. The previous bushing has a nice rubber lip to locate it.
Any luck contacting the manufacturer?