Underline & "- T SWISS T -" on Rolex Daytona around 1 million serial...

What we see is that Rolex used an additional 2 lines before & after the TSWISST on early Rolex Daytona 6238 & 6239 after they have printed the underline on top of the dial.
As we saw earlier the underline goes between '62-'64 on serveral other references...

Not only the underline up on the dial under we see here at Stephan's example with SWISS only print, 923.xxx serial:


Is the underline by "- TSWISS -" also a first sign that no radium was used on the dial? Seem to be in the correct serialrange for underline.
Here a nice and rare example from Kamal with a 1 million serial...


And another like above but now without the writing Daytona from Wannabuyawatch...


and a 1,1 million 6239 from Ben has also " - T SWISS T - " ....


Maybe one of the rarest versions are in possesion of a important italian collector..
Besides the " - T SWISS T - " we see that T SWISS T is printed twice on the dial..


Imho the - added to T SWISS T has to do something with the underline = tritium period.

What do other's think?

regards Philipp