I have the same caliper too. This past friday night I welded a brake tab on my stock peugeot forks. I had to flip my wheel around around as well as my fork tubes to make sure the old brake tab didnt hit the mounting bolts. a 2 inch piece of scrap metal and a little time is all you really need. I started at 4 removed the forks then fully disassembled the forks swapped the tubes removed old brakes. mounted new disc, then welded the tab on waahla. finished. I dont see why everyone doesnt have disc brakes.
ps the brake disc i got matched up perfectly with the peugeot hub. so it was so fucking easy to line up and get centered.
i got the pair together for 35$