replacing tires is a nightmare. I damaged my rear tire at about 5000 miles and ended up putting a shinko 805 big block adv tire that was 180/130/17 and it fit and is just a hair off from the original size. I am now at 10000 miles on the bike and my front is bald, I hate it, but the best option I have been able to find to replace the front is a shinko 705 which is a 70street/30dirt dual sport tire thats 120/70/17 (as opposed to 110/70/17 factory) They also make the 705 in 180/130/17 so I will probably end up getting the set even though I really am not pleased about it.... The knobby offroad looking tires are my favorite thing about the bike. Its what gives it its entre identity and character. Only to discover replacing them once they wear out is impossible, its maddening!
Look up the Tacoma World tire size calculator comparison tool. I found it to be an invaluable resource when tire shopping.
If you search over on the svartpilen 401 reddit page (my redit name is tomahawktaxidermy) I made a post where you can see pics of that back tire right after I mounted it. Sorry for being too lazy to look up these links, I got way too much work to do today.