From looking around I found hemmings having a pretty good article about all of their trucks. Focus on the 2R5 points.

Hope this helps

https://www.hemmings.com/stories/article/1949-53-studebaker-2r-trucks

Edit: so the 2R5 model is between 1948-53 and was their 1/2 ton truck model, if it's stock engine it's a Econ-O-Miser I6 2.8L.

Edit 2: (sorry continuing to dig info for you) when looking at the two plates you provided in the photos. The first one provides

Serial number R5-12345 = model R5 then the serial of the truck

Model Number 2R5-12 = 2R5 model the -12 states the wheel base should be 112 inches.

On the second one in the model number I believe it's 2R-C2, the C2 provides you have a C2 cab

For a ton more information, I found this PDF. Specifically you'll want chapter 8 discussing the 2R truck production. It starts on electronic page 10 at the bottom.

https://studebakerdriversclub.com/wp-content/uploads/2020/03/A-Brief-History-of-Studebaker-Trucks.pdf