If you don't have any luck finding a replacement, I was thinking the same thing as @Tunedpipe , you could probably make something. Just need something to bend the wire accurately. Or else it's going to be a belly lander for grass fields.
dont know the dia of landing gear wheels or metal rod .but if you have a propane torch and a hardware store. you can buy some piano wire heat it up with torch and a glove on wire holding hand or vise grips on it and bend it to size and mount that wheel to it and then to plane. all in all should not be that hard of a task to fab one