The original aviator series which had cream lettering on the faceplate, and silver grill cloth was discontinued in favor of an upgraded Aviator Gold series. This was due in part to changes in the grill cloth forcing such a change.
The Aviator Gold series was sluggish in sales, and never really "took off" making the product increasingly expensive to produce. We finally made a decision to end of life the product rather than raise the prices and further kill sales.
If you have one you are very lucky the amplifier was just AWESOME!