I do not have your steering parts but I do have some insight into why Acreage Outfitters might be having a hard time getting a hold of them - actually, it is likely that anyone would have a hard time getting steering shafts or parts right now.
I've heard a
rumor that Kubota's Japanese supplier of steering shafts and parts is having difficulties getting their parts out the door to Kubota's warehouses. Folks cannot find a new steering shaft to save their lives right now until Kubota and their supplier get everything sorted out.
You have the right idea looking for a used replacement. Give these folks a call and see if they have something in stock for you:
http://www.wkytp.com/ - they part out 100s of Kubotas on a regular basis and I know a lot of other forum members have been helped out by them before.
Good luck!