Luke,
The salesman data books do a pretty good job of spelling this out as all models even chassis type came with a LH light. I went into my '48 data book and Option No. 249 spells out the model availability for dual taillight/stoplight. It lists the following models, Sedan Delivery, Carryall Suburban, Panel and Canopy Express models. However in the 1949/50 books No.249 lists the following models, 1508, 3105, 3106, 3107, 3116, 3805, and 3807 (all with their own specific option number, i.e, 249K, etc.).It also adds the following quote, "The added protection of dual tail and stop lights is desired by many truck users and required by law in some states." So while I do believe they were equipped with the same basic light some left the factory with the RH light (I am talking a factory RPO not a dealer installed accessory).
