Mark XII: Tritium or Superluminova?

Hi all, I am new to this forum and this is my first thread.

Last week I bought a Mark XII (324101) second hand. I got it with the dial
inscription SWISS MADE, with no T's before and after. This watch had 3
services since it was bought 1997. In none of the service receipts I can find
a hint that dial and hands have been exchanged from tritium to luminova. Here
is my question: Have IWC during the production of this watch (1993 to 1999)
used tritium the whole period or switched to luminova from a certain time?
Thank you for helping!

Most watch companies stopped using Tritium during 1997 / 1998. Maybe IWC
stopped earlier.

The fact that there is no "T" on the dial would indicate the dial is SL.

If the hands and dial still sustain a glow, then it certainly is not Tritium

Thank you, guys, for your responses. There is certainly no tritium on dial and
hands of my Mark XII any more. Therefore my questions was whether IWC produced
Marx XII's with superluminova (or do I have to accept that dial and hands have
been replaced later).