The horns in this sub-gallery were all built by Max Keilwerth at the time when he was working independently: after his time at Adler & FX Hüller, and before he was employed by Hohner. These horns are German in origin. The majority of saxophones that Max Keilwerth built can be clearly identified by the Pure Tone Trademark stamp just above the serial #.
Admira
Apus
Apus

(Helen) I am not at all clear that this alto was made by MK. The key guards are way more modern than anything I have seen from him before. 

They only thing that says "Max Keilwerth" is the Pure Tone Trade Mark MP that would have come with a MK saxophone. 

I wonder if this may not have been a JK-made or inspired horn. Or something made through Heimarbeit? 

Hopefully we will find more of this brand in the future and the origin of this horn will be answered. 

Aristocrat American
Bb Tenor - Silver Plate - 21carsten on eBay
Bb Tenor - Silver Plate - 21carsten on eBay
The ad reads:

Verkaufe:
gebrauchtes Tenor Saxophon von Triumpf bei Keilwerth ohne Seriennummer

- Spielbereit vor nicht allzu langer Zeit überholt worden
- Alle Klappen leicht beweglich und gut spielbar
- S-Bogen mit Feinstimmer
- normale Geruchsspuren
-besondere Gravur: von Herrn Reichel " Die Frauengestalt"
- Koffer
- Rest Siehe Bilder

Privatverkauf (keine Rücknahme oder Garantie)
Bei Fragen bitte vor Gebotsabgabe kontaktieren

Ceasar
WENZEL FRIED stencil - Eb Alto serial # ?
WENZEL FRIED stencil - Eb Alto serial # ?

Nickel Plate

(Helen) I am not 100% sure this is an M.K. horn. However, this is as good a place as any to put it for now. I will need to do some digging and see if I can find some info on the name.