Hi Rob, and welcome to the TR club! You have a late 1963 TR4 (or maybe an early '64). The number you have (28394 CT) is the body shell number, and should be on a small aluminum strip pop-riveted to the body, left of the battery. It will be close, but not match, the actual commission #. That was on a rectangular tag to the right of the battery, and started with 'CT'. The engine & transmission will also have numbers stamped into them, and while they didn't match the commission #, they were usually close. Of course, after 60 years these often got replaced and might not be original to the car. These numbers might give clues to when your car came off the line if original. Hopefully you will find the commission tag in a box.
You car might have a 'metal' dash, originally painted white, or it could have come with a wooden dash fitted over the metal. This is important to know so you can figure out what glove box door you need. Look around in the car, trunk, or boxes for a metal door, or remnants of the wood dash.
Have fun - Jeff