Also, if you are trying to replace faulty wheels, Tredit has a lifetime warranty on their supplied wheels. So check with them if that is the case and they can set you up to get replacements sent. Otherwise, they may still have some of those available. I know we had those wheels on our previous 2013 Big Country.
By the way, from previous experience looking these up, they are Sendel T04 wheels. You can Google that and maybe find someone that still sells them.