Marlin made their .22 rifles for Sears, Roebuck & Co., which marketed them in the 1930's as their "Ranger" line. Sears does and did this with many items, such as appliances made for them by various makers, marketed under their "Kenmore" brand, or tools made for them, marketed under their "Craftsman" brand.
Marlin made their 1930's era bolt action .22 model 65 for Sears, which was marketed as the Ranger 34.
The Marlin model 50 was marketed by Sears as the Ranger 34A, with the A presumably meaning "auto." After the Marlin model 50 was dropped in 1935 or so by Marlin, and replaced with the model A1, Sears began offering that gun instead, also calling it the Ranger 34A. So a gun called a Ranger 34A may be a model 50, or it may be the more common model A1. The model A1 is a fun .22 semi-auto, but it is not open bolt. Additionally the model A-1 takes a different magazine, commonly called the model 80 magazine, which Marlin still makes (although all the different Marlin guns that took it are discontinued). In fact, I believe that Marlin has kept all of their .22 semi auto magazines in production up to this date EXCEPT the orphaned magazine for the model 50. The point being, if a magazine is said to be for the Ranger 34A, that can mean it is an elusive model 50 magazine, or the very common magazine for the model A1.
Some parts, such as the rear sight interchange between the A1, 65 and 50. The A1 and model 50 sort of resemble each other in that they both have a tubular receiver and a similar cocking handle. However the A1 has a different shaped magazine well, and the metal escutcheon for the mag well is a separate part from the trigger guard on the model A1. The A1 has an extractor that is visible on the side of the bolt, whereas the model 50 has no extractor in the bolt at all.
Above is a close up of the action on an early Ranger 34a/marlin A1. You can see the bolt has an extractor in it. The magazine well is further forward than on a Marlin 50, and the metal around it is separate from the trigger guard, unlike a Model 50. The magazine pictured is the one for this gun, and for a host of other Marlin .22's. Later Marlin A1 guns have a different trigger guard, and safety. This one most resembles the Marlin 50.
Here is a top view. The safety is a sliding lever at the rear of the action.
Above are the barrel markings on this Marlin A1/Ranger 34A. The rear sights are the same on this gun and the Marlin 50.
Here is a right side view of this Ranger 34A.