Correct Seeder Part CAD

I have the original seeder-dropper part (rusted but still dimensionally reliable) and the first replacement that a shop produced from their own STEP file. Unfortunately the new piece came back with incorrect dimensions and will not mate cleanly with the surrounding assemblies... (Budget: $250 - $750 AUD, Jobs: 3D CAD, 3D Design, 3D Drafting, 3D Modelling, 3D Printing & Rapid Prototyping, 3D Rendering, CAD/CAM, Solidworks)