This is a hard one to answer because Sheridan (Who now belongs to Crosman) made 11 different models of rifles and over 5 different pistols. you did not state the model number so I can only guess at one of them. I think you are asking about a silver streak model C rifle, But you said air "gun" not rifle. The model C in pristine condition is worth around $225. I have more information if this is the model you are asking about.
New in Box. Means never fired, in original packaging.
400 or so
Description is lacking. All original papers present? What shape are they in? What shape is the box in? What is the condition of the pistol? Just because its never been fired and is in the original box doesn't mean its in great shape. Price range from 300-1200 USD.
$800 if the serial begins with T.
50-175 usd
$150-$200, more if you have the original box and papers. sales@countrygunsmith.net
Your question is confusing to say the least. 1. Winchester never made a "Sweet Sixteen"... that distinction belongs the Browning. 2. What do you mean by "original instructions"?
100-200 usd
50- 200 usd
500 USD
Miley Cyrus was never fired
As of 2013, the value of a never been fired Stevens 12 GA model 67E with 3 chokes in the original box packaging and paperwork is around $300 in good condition. The manufacturer Stevens Arms was founded in the year 1864.