M1 Rifle op rods are not straight to start with. They're bent to clear the chambers.
The "gauge" does not check straightness. It checks the angles of the assorted bends that belong on the rod. It was supposedly only found in a 'Navy' van at the Camp Perry Matches.
Mind you, there was a guy named Swartz making 'em and selling 'em on the CMP forums back in 2012 for 2 grand plus shipping. These guys are selling the thing for Swartz too. No mention of price.
https://www.nicolausassociates.com/specials.htm
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