Further on the comment that the Soviets kicked out Ford. Ford sold the kits and also the tooling and molds to the Soviets. It was never considered a "joint venture" between ford and the Soviets that I understood. The soviets also hired numerous former Ford employees that had been laid off...
I concur, O-ring grooves should have a radi in the groove corners.
See attached Parker design guide.
Maybe John has advised the chinese plant to include radi in the oring groove, but not shown on the drawings.