Marc,
The Swiss 06/29 curves upwards. The center of the milled out portion is marked with the SIG logo (as SIG produced these frames).
CNC tooling was not used during the post war Mauser production. The cutouts were made by several horizontal and vertical milling/cutting machines. Although the drawings and jigs were based on the Swiss design, all tools, jigs and production steps had to be redone, because of differences in standards, calculations and production methods. Only a handfull of Swiss jigs and gauges found their way into the Mauser production process.
Mauser used relatively standard cutting, drilling and milling tools for the job.
The deletion of the two vertical 'inner ears' makes sense. They are completely pointless anyway
