Regular Production Option means that it was
optional equipment. Some states might have required dual tail/stop/signal lamps. I think that WA state had an early requirement. The dealer would have added the RPO to the truck-order from GM, or added a non GM set at the dealership.
The RPO 249 was available in 1956 on models 3105, 3106, and 3116
"Are you assuming the RPO 249 is NOT the standard rear side panel light? "
I am assuming nothing. I am taking this from the GM Specifications Manual and the Chevrolet Truck Data Book.
"I forgot why we are discussing this"
I do not know why you are discussing this.
Before you posted "Just to be clear . . ", I had noted/asked "You might have GM accessories/options or you might have other makes. What markings are on the lenses? GM dual lamps are hard to find and are expensive. They are sometimes available at swap meets and on eBay (most likely high prices, if GM?)."
I am not interested in bantering with you. I was providing factual information (from GM documents) to the original poster.
If you are certain that he has RPO lamps, that would be quite useful factual information in helping him find replacement parts.
