Giddyup 'n Go

Giddyup 'n Go is a miscellaneous quest in Fallout 4.

Detailed walkthrough
Talk with Arlen Glass in The Slog and ask him for work. He'll express his interest in the toy Giddyup Buttercup and say he needs some spare parts, which can only be found in the Wilson Atomatoys factory, for his work on them. If asked for a reward, he'll offer a base payment of 150 caps and can be pushed into offering 225 or 300 caps with some speech checks. A third reward speech check, if passed, will give a Wilson Atomatoys ID card, used in the quest.

When you reach the factory, it's likely that the super mutants that inhabit the place and nearby Gunners will be battling each other. They and the super mutants located within will need to be fought through to retrieve the toy parts. A minigun wielding super mutant named Big Mack, leader of the small group, will also be found inside. Being so far south and right next to Quincy, this is a very dangerous area. Being a higher level and well-prepared is recommended when doing this quest.

After killing the mutants, head to a small room in the back of the factory with a door that requires an ID card to open. To get in the room with the quest parts, get the card located upstairs over at the right of the desk in the corner on the ground. Alternatively, it may be found on the super mutant overlord, or other mutant leader, found outside or inside the factory. If the third speech check was passed with Arlen, you'll already possess one. Once inside, take the toy parts found on a shelf to the left of the room and return to The Slog.

Talk with Arlen again and give him the parts. In his excitement and awe, he'll gladly give you the caps reward agreed upon, ending the quest.

Bugs

 * Arlen Glass may be unresponsive or found dead at the Slog. Using the 'kill' and 'resurrect' console commands will allow you to complete the quest.
 * You can accidentally scrap the parts and be unable to finish quest.