This is an Antigua Winds model 4240 “power bell” alto saxophone with silver plated body and gold plated keys.
I’m a professional player of more than 30 years and used to be an Antigua Winds artist. 

When I got this horn a couple years ago it was badly tarnished and unplayable. It has been overhauled and it plays great.
When the scale on the keys was removed some of the gold plating came off as well, see the photos.
This finish on these horns is somewhat rare.
At a short distance, she shines like a beauty. Up close, there is still some stubborn tarnish under the keys that can only be removed by complete disassembly. But it’s just the finish.
I can easily play over 3 octaves on this horn and I played this horn on a few gigs with no issues. 
I can send you a video if you provide an email address.
I still play Antigua horns and play more than 150 gigs a year.
These are similar in design to a Selmer Super Acrion 80 series 2, and play like them, at a fraction of the cost.
It comes with a contoured Kaces case. It has some wear, but is fully functional.
It’s a great playing pretty horn at a great price!
Shipping to the continental USA only