what condition is the rifle in.
It was made in 1974.
The Sheridan Silver Streak is a 20 cal pump air rifle. To get an estimate of value please state the condition of the air rifle. Is it working? Is it in poor, fair, good, very good, or excellent condition.
It was made in 1975
Sheridan C silver streak in good condition would be worth between $125 -$160 USD
Sheridan made several C series rifles. I assume that you are asking about the C Silver Streak. Not the C9 Sliver Streak. In order to give you an estimate I need to know the condition of the rifle. Does it still work? Does it hold air. What condition is it in? All these determine the current value.
Here is the link to all of the manuals for Sheridan and Benjamin. Crosman owns Sheridan and Benjamin See the link below.
There are 3 versions of the Sheridan Blue Streak. See the link below for the 2nd version. BTW today Crosman owns the Sheridan and Benjamin line of air guns. This link is from Crosman
Depending on which version of the Silver Streak, the C Series or the C9 Series the value is about the same. In Very Good condition it is worth around $135 to $155 If it has no wear, scratches, dings, rust, pitting or other damage.
The Blue Streak has been in production from 1995 to present. If you want more Information I suggest you contact Crosman who owns both Benjamin and Sheridan. See the link below.
It's very hard to date a Sheridan rifle. Let me explain. Sheridan started in 1945 and produced single shot air rifles. In 1977 Benjamin air rifle bought Sheridan and continued the line. In 1992 Crosman bought Benjamin. And again kept both names in manufacture. They decided to use Sheridan on the 20 caliber rifles and Benjamin on the .177 and .22 caliber rifles and air guns. At one point you could find both names on the rifles. In 1995 they came out with the C9 Silver streak model which later added the CB9 Blue streak model. there have been 4 different variations of the Blue streak. It's still made today. Crosman made some changes with their serial numbering system and I can't pinpoint your date of manufacture. See the links below
I believe you are asking about a Sheridan .20 cal (5mm) air rifle. They started to make this rifle in 1949 and stopped in 1990 ( sheridan sliverstreak model ) During the 1990's the name changed to C9 sliverstreak and C9 bluestreak. The value is determined by the current condition of the rifle. You did not give any such information , therefor I can not answer you.