Oh yeah! I went around to a few recycle shops looking for a spare and got laughed out of th shop.
"You want a what? Why sonny I haven't see none of those since the seventy's when they made rear drive cars."
I thought "Sonny' was a nice touch since I'm 68 and he was at least 20 years my jr. 14"s are plentiful at $20.00 apiece,so I may change when the rubber says it's time. Meanwhile I have one of those 15" temporary spares that I carry and the outside diameter is close to being the same as the regular 13" wheels on the trailer. Local trailer Rv place had a rim but he wanted $150 and I'm too thrrrrifty to pay that.