Normally so should it be Tritium when it says T<25 at the dial but there
is some replacement dials from the late 90's and early 20's that have this
marking at a Luminova dial. The easiest way to check what you got is to
put the watch for a minute below a strong light and if it glow strongly green
so did you have a Luminova dial. I never seen a T<25 dial with WG borders
that have Luminova, I believe it's only at the first matte replacement dials.
Today they says SWISS.
I hope it helps.
Jocke