I cannot speak to the scabbard, but that maker mark is a legitimate mark used by Zeitler on TR edged weapons.
It is one of the marks I have seen on Luft2s.
Luca, the dagger seems to be a late production HERDER army (at least the crossguard is). Socalled "swirl pattern" scabbards have been produced during the period (late) and have been faked postwars. To me it looks like a period produced one (I think also used by HERDER) with the proper scabbard bands.
The exact ZEITLER mark is shown by TTW in his army book (erroneously ! as distributor mark).
The whole dagger looks homogeneous so to me it seems to be a legit, period produced (rare) ZEITLER army dagger but an in hand inspection for a final statement would be best.
BTW, my personal feeling is that you should at least mention that you have put the same question in another forum.
B generic scabbard is known to have swirls.. and this is a B gen.. Kevin.
oh i'm extremely sorry not to have mentioned that i posted in another forum...and thanks for help
If i'm not wrong Zeitler is one of the very few WWII german blade makers outside the Solingen/Suhl area
Not only was Zeitler one of the few German blade makers outside the Solingen/Suhl area, Zeitler was outside Germany itself.
ZEITLER was a producer (NOT distributor) in Vienna/Austria (at these times "Ostmark" after annexation). The firm had itīs origin in the imperial Austria. After annexation it used mainly parts of other firms or generic parts but -as research says- still did produce the heart of each edged weapon, the blade, in house.