V
The Tektronix Type V is a video plug-in for 500-series scopes. It never went into full production.
Larry Biggs was the project leader. Ron Olson did the dual-trace vertical. Phil Crosby did the sync, D.C. restorer, and line selector. The design was started in late 1959. The plan was to have a plug-in that could functionally replace the 524.
See https://vintagetek.org/television-products/ about a third of the way down is a blurb about the V unit.
Although the V unit never made it to market, Ron Olsen ended up using much of the dual-trace vertical design in the 1A1.