Generally there are 3 types of Swiss made in Speedmasters.
1. Swiss Made (no T’s).
2. T Swiss Made T (narrow T’s).
3. T Swiss Made T (wide T’s).
However, there is also a forth that came between the no T and narrow T dials. It’s believed that some tritium dials originally came with no T’s, however in around 1963 legislation was passed that required dials containing tritium lume to be marked as such. As a result, some early tritium no T dials had T’s added retrospectively. As these T were not added at the same time as the main dial print including ‘Swiss Made’, the T’s sometimes seem slightly misaligned to the Swiss Made, often slight higher.