The 5207P has been produced in very low numbers over the years and rarely comes up for auction. Phillips sold a double-sealed example
link in 2020 for CHF 567000 while Antiquorum brought one to
link market in 2018 that went for CHF 509000. The watch world
link is in a different place now than it was even just two years ago so it's really hard to guess where lot 143 could end up. Sotheby's thinks it'll go somewhere between CHF 500000 and 800000.