Can this £30 bottle of Steel Seal save my cheap V8 Jaguar?

After more troubleshooting and trips to the garage with my troublesome Jaguar S Type, there's reason to believe that my car might be suffering from a failed

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Can this £30 bottle of Steel Seal save my cheap V8 Jaguar?

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Head Gasket Sealer for 8 Cylinder Engines - Steel Seal

Synthetic Oil Causes Gaskets to Soften, Leading to Oil Leak

Synthetic Oil Causes Gaskets to Soften, Leading to Oil Leak

Synthetic Oil Causes Gaskets to Soften, Leading to Oil Leak

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Head Gasket Sealer for 8 Cylinder Engines - Steel Seal