Go to your MF dealer and ask what other optioal tyres fit, as there will be 100 and 200 series tractors running this size tyre. Then go to a wrecker.
Also there will be later series tractors running this size tyre, but I have no idea of the models.
Note specify PAVT tyre. This refers to the type of rim.
Another option may be to go to wider tyres on regular Ag rim, while keeping the rolling radius(diameter) the same(zero effect on gearing). There are often tyre width option ex factory.
As chim says the other side is probably close to failure too, so get a pair, budget permitting.