"not Allegro, Cilo or Mondia" as Juvela says, this does not visually align with any of the "Big 3" Swiss marques, but to me that 6-digit serial number in that location is more like a Mondia (or Juvela) than the other 2, but no cigar.

And don't know that any Swiss brands ever used Durifort tubing, mostly 531 and later some went to Columbus.

I haven't seen much of any Tigras but now I wonder...