Beitman 1950, page 128 (you need djvu to read them)

http://www.schmarder.com/radios/beitmans/index.htm

Schematic shows it as a shield around the cap from volume to V3 grid.

These days we'd probably mount the cap somewhere and run a shielded
cable but in point-to-point the components themselves often double
duty as 'connecting wires' so they've constructed a shield around it.

Looks like a brute force, last minute fix for a poor chassis layout problem.
It looks like the point to point run is longer than just the capacitor leads
would allow.

Phil B