Hello, I’m new here. Have an older car trailer (Bj 78) with an acceptable total weight of 800kg. In the vehicle license is the tyre size 75R14. However, this is no longer available. Mounted are 185/60/R14 82H. At the main examination at GTÜ it was criticized that the tyres are not allowed. Where can I find a permissible spare size? I found nothing suitable.