Below: a set of detailed photographs showing the exemplary standard of design and construction employed in the Pratt & Whitney compound slide assembly: the "end plates" and bosses on both the top and cross slides were held on with four bolts (rather than the usual two), the feed dials thinned down on their leading edge just like the thimble of a real micrometer and the balanced ball handles were secured - Rivett-like - with screws that passed down the length of their cross shafts..