Having not finished the '59 TR3 purchased a year or two ago, I saw no reason not to buy a '57, which is what we actually wanted, to replace the one sold 40 years ago. Anyway, now there's two. Hopefully they do not mate, but that tends to happen with this type of junk. The '57 runs and drives at least so that will make procrastinating on the '59 easier.
The problem is, roughly 20 years ago, prior to our purchase, the '57 became a '58, on paper at least. In fact the paperwork is so official that it somehow completely changed the VIN plate attached to the car with two pop rivets. Fairly common on old British cars... or Fords or Chevys. I was aware pre-purchase. Unfortunately, there's no way to determine what number was stamped into the plate the car was born with. So, I'm thinking if I can find a '57 VIN plate and/or title, two wrongs might make a right or at least less wrong. Anyone have such a thing? Woody had a TR3 firewall, but it too had elusive VIN and body plates. Surely there's a rusted out small mouth TR3 out there that can be mailed in a business envelope. Anyone??
Two wrongs don't make a right... but three rights can make a left!
Is there a number stamped on the chassis?
When talking about TR3 you are actually talking about Commission Number Plates.
The Roadster Factory sells Commission Number Plates for TR3s for 10.95. Part number CNP31. They also have TR2, TR3A, etc. Number Plates and Labels: Tracing Your Car S History , TR2, TR3 :(page 3) (zeni.net)
There should also be a body number plate. You could contact British Motor Museum and provide your body number and they may be able to provide you with the commission number.
British Motor Museum | Heritage Certificates
Unfortunately this TR3 inherited the commission plate, body plate, and engine from the TR3a donor. So the TS #, EB #, and the engine # all say it's a '58. AFAIK, there's no way to determine the commission # without the plate.
Yeah, you got a sticky wicket there.
I'd try the Triumph Register of America. I am not a member but used to know some folks that were members. Nino Richards is the tech consultant. Sorry, I don't have his email. TRA has a forum that they ask for a donation to use.
There is also the Vintage Triumph Register but I have been out of there for years so I have no idea who to try contact there. I believe you need to be a member to use their resources.
Try talking to Ted Schumacher at TS Imported in Pandora, OH. He is a great wealth of info and I stay in touch with him a lot.
Have you checked the diff or trans number? Or do you suspect that they may have been changed also?