The early split bell key saxophones have a MK period bow guard (see picture) and a full naked lady engraving by Fritz Reichel, who not only worked for F.X.Hüller but other companies too.
This soon changed into the characteristic fleur-de-lis shaped bow guard, and not much later the naked lady gave way to more elaborate art deco engraving. However, common engraving remained possible for those who were not ready for this artistic style.
Almost every stencil has a different one, and the “’World de luxe” models which probably were custom engraved.
Occasionally, the name F.X.Hüller & Co was engraved on the bell too.
The variety in finishing was quite impressive too: nickel plated, silver plated, matte silver body, bell, neck and shiny silver-plated key work, lacquered, partly unlacquered, gold plated, matte gold body, bell, neck and shiny gold-plated key work, both matte gold and silver body, bell, neck and gold-plated key work.
They kept decorating their saxophones this way throughout the entire saxophone production.
The first period contained three models: ''Professional'', ''Champion'' and ''World de Luxe''.
The ''Professional" had a three-ring micro tuner, no front F key, no little Bb key, no extra triller keys and a small left hand pinky-table ( see pictures Johannes Adler tenor, fifth row )
The “Champion” had a three-ring micro tuner, a front F key, no extra triller keys.
The “World de luxe” (also called “World luxus”) had a three-ring micro tuner, a full mother of pearl treatment, G-G#, C#-D and high and low D-D# triller keys and a beautifully shaped low B key protector.
Late ''World de luxe'' models had an improved left hand pinky cluster, a shortened high E side key and the name ''de Luxe'' or ''Luxus'' engraved on the bell ( see pictures 4 and 5 of the World Luxus alto on the ninth row ). The early de luxe models, were simply called ''World'' but they practically had the same features as their successor.
All split bell key saxophones have a straight body-to-bell brace.

At first I saw "Professional'' as one of the many FXH stencils.
Until Tobi, a German collector discovered that ''Professional'' was no stencil at all, but in fact a regular FXH model during the 1st and 2nd period.
Recently Tobi also managed to get hold of a 1934 FXH cataloque, this cataloque proofs he was right about the ''Professional'' model, but it reveals way more then that!
In the beginning of the 1st period FXH offered one model only: a very luxurious saxophone, simply called "World''. 
Because of the economical crisis the company decided to renew two former models and offer them again: the ''Champion'' and the ''Professional'', plain saxophones, both for an affordable price.
On request of the FXH cuctomers, a more affordable and therefore less luxurious version of the ''World'' model was now available too: this horn became the new ''World'' model.
For those who still could afford it: the most luxurious model stayed available, but was now called ''World Luxus''.
The ''World Luxus'' alto saxophone could be custom ordered aswell: keyed from low Bb to high G or even keyed from low A to high G.
The ''World de Luxe'' baritone saxophone is the only bari with a micro tuner i've ever seen.
More details of these models: on the copy of the old FXH cataloque pages here below ( eleventh to fourteenth row )

Why are the bass, contra bass ( eight row ) and the low A to high G alto ( tenth row ) unlaquered and not engraved?
After the war German musical instrument companies in Graslitz were confiscated with everything in it and integrated into the Amati collective, the owner of those three saxophones.
Could it be FXH stiil had them in stock, perhaps in parts, waiting to be ordered, waiting for an engraving and name on the bell?
Not necessarily ''World'', it could have been ''Klingson'' or ''C.A. Wunderlich'' too?
I can imagine rare saxophones like those three were only engraved and named after being ordered.
Perhaps they were found in the Julius Keilwerth company where, from may 1945, most brands were centered?
To me it's not unlikely Amati putted the parts together and assembled them.
According to the 2016 ''Faszination Saxophon'' cataloque the alto was not recognized as a FXH saxophone, this could explain why it has no ''World'' sticker like the bass and contra bass?
( an exchange of views on this matter took place at the ''Contact'' page )

pic above: World Luxus alto source
first row: pic 2 source / pic 3 source Tobi / pic 5 source kultura Wroclow
second row: pic 1 source 400 jahre Instrumentenbau Graslitz Katalog, coll. W.Kenz / pic 2 and 5 source / pic 3 source Tobi / pic 4 source
third and fourth row: C.A.Wunderlich alto ( very early FXH stencil ) 
fifth row: Johannes Adler tenor ( FXH stencil ), no front F key, no little Bb key and no extra triller keys 
sixth row: FXH Champion alto
seventh row: FXH World de Luxe tenor ( two naked ladies engraving )
eight row: pic 1 FXH bass saxophone with double C tone hole ( FXH copyright 1087538 ) / pic 2 & 3 FXH contra bass saxophone / pic 4 & 5 FXH World de luxe sopranino pic 1,4 & 5 source 400 jahre Instrumentenbau Graslitz Katalog, coll. Amati-Denak / coll. W. Kenz
ninth row: pic 1 & 2 FXH World de luxe soprano source / pic 3 to 5 FXH curved soprano source Vaclav
tenth row: FXH alto keyed from low A to high G source Tobi
eleventh to fourteenth row: 1932 FXH cataloque source Mönnig Company ( V. Schindler )
fifteenth row: FXH metal mouthpiece with adjustable tipopening ( FXH 1932 copyright ), also available without the adjustable tipopening source Intune
sixteenth row: World mouthpiece with metal table and tip, also available without the metal table and in different colors, both models came in one tipopening only / very last picture FXH World split bell key baritone, detailed pictures will follow, after restoration
seventeenth row: FXH metal mouthpiece with adjustable tipopening, these mouthpieces were available for alto only

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