Retno Kellison J4 Roadster Reproduction Bodywork – Fiberglass Race Car Body

Retno Kellison J4 Roadster Reproduction Bodywork – Fiberglass Race Car Body

Bring your race car build back to the track with the Retno Kellison J4 Roadster Reproduction Bodywork, manufactured using a proven fiberglass layup schedule designed to provide a lightweight structure with added impact resistance and rigidity.

Designed for the Kellison J4 Roadster, this reproduction bodywork features a one-piece body design along with separate doors, door inner panels, front and rear trunk lids, a headrest, and a fuel access panel. It is well suited for restoration projects, replica builds, vintage racing, and performance applications.

What's Included – Kellison J4 Roadster Bodywork

This listing includes:

• One-Piece Kellison J4 Roadster Body
• Right Door
• Left Door
• Right Door Inner Panel
• Left Door Inner Panel
• Rear Trunk Lid
• Front Trunk Lid
• Headrest
• Fuel Access Panel / Flap

Made-to-Order Product & Lead Time

Please Note: All bodywork is made to order. Please allow 10–14 business days for your order to be completed. Production time may vary depending on the complexity of the order and any custom specifications requested. We appreciate your patience while we craft your bodywork to meet your needs.

Standard Fiberglass Layup Schedule

Our standard race-car fiberglass construction uses a carefully layered combination of gel coat, fiberglass mat, structural E-Glass cloth, and polyester or vinylester resin. Each layer serves a specific purpose in creating a strong, lightweight body panel suitable for racing and performance applications.

1st Layer – Gel Coat
A gel-coat surface layer provides the foundation of the panel and helps create a consistent finished surface.

2nd Layer – 1.5 oz Fiberglass Mat
The first fiberglass layer uses 1.5 oz fiberglass mat combined with polyester or vinylester resin. This layer begins building the panel's initial thickness and structural foundation.

3rd Layer – 2 oz Fiberglass Mat
A second layer of 2 oz strand fiberglass mat is combined with polyester or vinylester resin to further increase the panel's strength and rigidity.

Final Layer – 6 oz E-Glass Structural Cloth
The backing layer consists of 6 oz E-Glass cloth (60 sq.) combined with polyester or vinylester resin. This structural backing layer provides additional reinforcement and helps complete the standard race-car layup.

Reinforced Flat & Horizontal Panels

For flat or horizontal panels where additional rigidity is required—such as the front trunk lid, rear trunk lid, fuel access panel, and other large flat sections—we can incorporate high-density foam core or balsa strips into the construction.

These reinforcement methods help minimize panel flex without requiring additional external structural elements, keeping the overall design lightweight while improving rigidity.

Professional Finishing Process

Peel ply is applied during the layup process and removed after curing to help achieve a proper surface finish and prepare the part for subsequent finishing or installation.

Custom Materials & Construction Available

Need something beyond our standard fiberglass construction?

Retno offers additional material options upon request, including:

• Carbon Fiber
• Matrix Fiber Mix
• Retno Exclusive Barotex Fiber

Material selection and custom construction can be tailored to your specific application and performance requirements.

Custom Bodywork Requests

Because every race-car build can have different requirements, custom bodywork requests are welcome.

For custom dimensions, modifications, material upgrades, special layup schedules, or unique bodywork requirements, please submit your request through our SOS (Specialty Order Shop) or our Custom Order Bodywork Form.

Custom materials, construction methods, and modifications may affect pricing and lead times.

Built for the Track

Whether you're restoring a Kellison J4 Roadster, replacing damaged bodywork, building a replica, or creating a vintage competition vehicle, the Retno Kellison J4 Roadster Reproduction Bodywork is designed with the needs of vintage racing and performance applications in mind.

Combining lightweight construction, structural reinforcement, impact resistance, and race-ready design, this reproduction bodywork provides a strong foundation for your Kellison J4 Roadster restoration, replica, or race build.