why would they
: redial a small T on yours

As you already know a "T" indicates Tritium is present on a dial as does "3H". While older Heuer branded dials may have both indicators, Sinn stocked branded Heuer refurbished watch dials do not. To the best of my knowledge, both Sinn stocked Heuer branded dials (noted by their fat XL Heuer logo and cut off numerals at the sub dials) and Sinn dials (which are almost the same as the Heuer branded ones) do not have a T printed on them. Sinn provided both Tritium and non-Tritium painted dials under both brand names. Tritium dials branded Heuer and Sinn have a 3H indicator only because it was not necessary for them to print both a T and 3H as the indicators essentially mean the same thing. Dials absent of Tritium have no indicator (T or 3H) because radioactive material is not present. I handled a dial just like this one, so I am fairly sure what you have there is a reprinted and installed in a an otherwise perfectly good watch. To my eyes, nothing about the dial looks original. If it's not a reprinted dial, the "T" was certainly added after to make it a more desirable dial and therefore, time piece. Reprinted or not, I doubt the paint is Tritium. It has just been made to look like it.