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CT and CTC commission numbers
Triumph TR4 & TR4A VIN Decoder
The Michelotti-styled TR4 and later TR4A use distinct commission-number families, making the original plate useful for model identification even though these cars predate standardized VINs.
Decoder coverage: 1961–1967
TR4 CT series TR4A CTC series
Decoder reference
What this decoder page is designed to answer.
CT and CTC identify the Michelotti TR generation
Triumph moved from the early sidescreen TR chassis system to the CT commission prefix for the TR4. The later TR4A uses the CTC family, so the prefix alone provides a strong model-generation signal before the serial is considered. PetrolJunky accepts common commission-number formatting and stores the normalized number with the vehicle registry record.
Why the chassis number matters
TR4 and TR4A cars can have decades of restoration history, drivetrain changes and replacement panels. The commission number is therefore more reliable for identifying the original model family than visual details that may have been changed. PetrolJunky does not claim options or suspension specification that the commission number itself does not prove.
One decoder for the rest of the site
This model page explains TR4 coverage for search engines and owners, but the decoder box remains universal: a BMW, Jaguar, MG or modern 17-character VIN entered here still follows the appropriate decoder.
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Recently updated TR4 / TR4A records
Decoder facts stay tied to the exact VIN or chassis number while owners decide what history and photographs to share publicly.
Public registry records matching this decoder page will appear here as the registry grows.
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