(Pete) There are four models of Guardala: Artist, Pro Custom, New York Series, and Earth Tone.
That's also in order of greatness: the Earth Tone Series is the top model.
Way more info on Helen's breakdown page.

Also check out Helen's new blog post about the Asian-made Dave Guardala horns.
Artist
Artist
DG-400: alto model
DG-500: tenor model
DG-600: Baritone model
GL: gold lacquer
BN: black nickel plate with silver plated keywork
SP: Silver plate
Rare examples in rose gold
Catalog
Catalog
From rsrsax on eBay
Earth Tone
Earth Tone
DG-403ET: alto model
DG-503ET: tenor model
Special HI-PULSE™ annealed brass
New York
New York
DG-402: alto model
DG-502: tenor model
BN: Black nickel plate w/silver plated keywork
SP: Silver plated with gold plated keywork
Special HI-PULSE™ annealed brass
Pro Custom (Goldbrass)
Pro Custom (Goldbrass)
DG-401: alto model
DG-501: tenor model
CL: clear lacquer w/silver plated keywork
BN: black nickel plate w/silver plated keywork