"Balkenkorn" is a blade
"Leuchtperlkorn" is a 2.5mm dia bead (in white only)
"Lumifix-Korn" is fibre-optic bead (in red and green)

The standard CZ550 front sight is 6.3mm tall and it does have a 11 or 1T marking on the underside, and looks to be about 1mm dia bead.

I've put in my request for a blade and a few size white beads - should resolve all issues with the 375 and let me shoot my cast in 458 with open sights (these were going much higher than the jacketed 400 and 500s).