Part Locations: Farm
The farm, like the Diner has three areas you can enter. There is the house to the right, the barn to the left that is already open, and a small shed in between the two that you need the turbine to open. Most of the parts for the turret are usually in and around the house, but sometimes a part or two can be found in the barn on both the upper and lower level.
Lawn Mower
The lawn mower can be found either in the barn to the left when you first approach, usually in the center of it, or it can be found behind the house to the right of the area. Go towards the rear of the house using the left side and it can sometimes be found against the fence there.
RPD
Couch in the corner on the second floor,
On top of a barrel in the barn
Box of Ammo
The box of ammo can be found on the shelf leading into the kitchen, on the first story of the house.