About the guide blade, I used a bigger one from my spares box. Using a sharp knife, files and sandpaper I carefully thinned the stem leaving a small ball at the end. I drilled a hole the right distance from the stem and fitted a short piece of thin brass for the small hole in the thin rod. The ball end of the stem had to be cut down quite a lot before I was able push the replacement blade into place. Because of my poor workmanship the guide was very shaky, but I fixed that with a thin spacer disc around the stem.