Master Cylinder Piston Retention Clip

Hello, Looking for the Clip that Screws into the rear of the Master Cylinder and Retains the Piston in the bore.

Prolly most any Single pot or Double Pot Cast Iron MC will do, from say '62-'76 With Drum Brakes or KH Calipers. The Ma MoPar Master cylinders I believe had an internal Retention clip.

Picture of my MC for reference... clip that is needed is missing.
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