I should add - reversing these by hand isn't as bad as it sounds. Injection molds are machined with a CNC setup, which have a limited set of routing bits, so any radii are generally to the nearest millimeter, or in detailed spots, 0.5mm or the occasional 0.25mm. Linear dimensions are almost always no more granular than 0.1mm, but even if some dimensions were originally intended to be a multiple of 0.05mm, rounding up or down to the nearest 0.1mm only throws you off by two thousandths of an inch, so it isn't generally going to be a concern. That's getting down to the tolerance of the mold.