Joe,

At Lonnie's Jim Carter link:
"With the total redesign of the step bed in 1954, the six volt taillights were also changed. They became round four inch diameter units with one light bulb having two filaments of three and twenty one candle power. The lens retaining bezel was chrome plated on the more deluxe truck, painted black like the bucket on the standard models."

There are stainless reproduction lamps available - the whole unit body/bezel is stainless. I'll paint the body semi-gloss black and polish the bezel (for a deluxe option appearance).

They also sell a black body with stainless bezel.

My guess is that this bezel is stainless?

Jim Carter sells a black body with chrome bezel/ring.

Jim Carter has an all chrome unit (with non-original-equipment) blue dot in the lens.