Athearn’s Ready-To-Roll™ GP35, based on the Rail Power Products tooling, represents a phase 1a version that was produced from October 1963 to February 1964. This was arguably the most widely used variant of the GP35. Some of the spotting features of this phase found on the model are:

• Multiple latch on the engine compartment doors
• Triple louver sets on the battery box covers
• Open top 36” radiator center fans
• Flat inertial air filter hatch
• Thick side sill
• Low profile fuel tank
• McHenry® scale knuckle spring couplers
• Fully assembled and ready to operate
• Scale Width Hoods
• Equipped with DCC Quick Plug Technology
• Directional Head Lights
• Prototype specific detail applied
• Photo etched sun-shades (where applicable)
• Foot-board or snow plow pilots
• Cast metal air horns
• Celcon Handrails
• See-through fans
• Hex Drive-Lines
• Machined RP 25 Profile Metal Wheels