If you have one of the nicro(ball) hones of a small enough size you could try a very light hone as long as you already have the kit, otherwise as others said get the Dave Silver one.
I would suggest checking the flexi hoses, the first US one i did the hoses were so solid i had to push a welding rod through to clean them, outside was perfect with no cracks or i wouldnt have bothered.
Strip and clean the caliper as well, if piston pitted replace with stainless plus scrape out the seal groove with a dental pick