You don't appear to have maintained these; no conditioner or waterproofer on the leather, no grease on the D-rings, etc. Apart from the sole, you also need to check inside the boot; is the interior fabric worn / torn near the ankles or at the heel? IMHO, and I've been through three pairs of Meindls, based on your photos, they are not worth repairing. If you've got 3 - 5 years heavy wear out of them they don't owe you anything. You could take them into the Great Outdoors and ask for an opinion, but why not just fork out about 250 euro on a new pair of Bhutans? You won't regret it.