I finally gave up on the stock tuners on my 255 (the plain stings wore grooves in the string posts, allowing the strings to slip), and obtained a set of Grover H97-18 Sta-Tite tuners as replacements. They seem to be a well constructed tuner for the money and have an 18:1 ratio, etc. I just wanted to put the word out for anyone considering this product that the string posts are longer than the originals, and modifications are necessary. The D and G string posts interfere with each other, and the tuners won't both mount flush without grinding about 2mm off of each post. It wasn't difficult: I mounted the tuner in a 1/2" piece of maple (with a hole drilled for the post) about one inch wide by six inches long to have something to hold onto. I then held the tuner post end to the belt grinder at a slight angle, and quickly spun the post with a hand crank for an even bevel on the end. It added about twenty minutes to my installation time. I wonder if the Schaller or Gotoh tuners for slotted headstock are the same?
chomp, chomp, chomp, chomp...