I have not studied Davidsen's rep's for 1:1 cloning accuracy. IMHO, it is more important to have great customer service, an accurate movement, pressure tested to 50 ATM, and a watch that will not fall apart after 6 months. If anything goes wrong, there are numerous testimonials online that he would repair the watch and turn it around to your satisfaction at minimal or no cost (depending on actual failure mode). These are all attributes of buying from Davidsen that I can vouch for. Also, he can customize your 'Francken creation' or 'tribute/homage' watch for you, i.e. if departing from a "need for a 1:1 gen" philosophy is acceptable to you. For example, I got him to build a homage for me that has genuine decorated Swiss ETA 6497 movement, with face and hands that I specified, and it came out beautifully. His lume out of the box is simply awesome - my sandwich dial implementation lasts a whole night long and is brighter than some gen's that I will not name. BTW, this is the article that introduced me to Davidsen: http://tinyurl.com/davidsen-marina-militare