It features snap action sprung switch rails headblock ties

Model Number: 1585

but there are many examples of these cars being shuttled between mills miles apart

RVOS01001T2

Here is a Magnuson Models 439-968 HO Scale Maintenance Truck Kit

Revell 2085 HO Gravel Plant Plastic Model Building Kit VariantsUnitPrice_number_17.60 It features snap action sprungThis is a Revell 2085 HO Gravel Plant Plastic Model Building Kit. Condition: Factory New (C 9) Operational Status: Functional Original Box: Yes (P 9) Manufacturer: Revell Model Number: 2085 Road Name: **** No Road Name MSRP: $59. 99 Scale Era: HO Scale Model Type: Building Kits The Trainz SKU for this item is P12376670. Trainz Product Id: 12376670