Stock switch? Which one is that?

Since turn signals were an option back then, the problem is...

There were TWO different turn signal switches used on 1953/55 trucks.

Factory installed and dealer installed. They are not the same.

Western Auto, Sears and autoparts stores sold a similar switch as the Ford dealer installed switch, which clamped on the steering column.

1949/59 Ford Passenger Car Parts Catalog: Illustration Section 130, page 402 shows the factory installed switch for 1953/54 Ford cars. Page 403 = 1955 Ford (not Bird).

These are the same two switches that were factory installed in 1953/55 trucks. Fit inside the steering column.