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
Some parts are available through Crosman (Crosman owns Benjamin and Sheridan) See the link below.
The Blue Book of Airguns has the info you need. Also, all Sheridan Streaks are .20 caliber, not .22 caliber.
The serial number is on the left side of the loading port, in front of the model number. It may be under the black piece of rubber plastic.
The Sheridan Blue Streak air rifle uses a 5mm pellet. This is about .20 caliber- larger than the .177 pellet, smaller than the .22 pellet. I have been able to get these at Bass Pro Shop. There are also at least 3 lots of them for sale on Ebay right now. Only the 5mm/ .20 caliber pellets will work in your rifle- do not try to substitute anything else. P.S. Have had one for years. These are extremely good air rifles- very accurate, very powerful.
Sheridan air rifles who is owned by Crosman Sheridans are 5mm air rifles
There are 4 different versions of the Silver Streak. Most list parts as 397. I am unable to locate any reference to part D279 1D. So here is a current drawing of the parts to a current sliver streak. Crosman has a parts list of most their airguns. Crosman owns both Benjamin and Sheridan. see the link 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.
What is the age of a Sheridan c series 5mm 20cal rifle serial number 370862
Sometime around 1980. In 1977 Benjamin bought out Sheridan and for a time they merged the names Benjamin/Sheridan.
It was manufactured in 1978
You did not state the condition of the rifle, so I am going to assume it is in "Good" condition, Not Very Good or fair condition. It would be worth between $85 - $105 add 15% for the Box and Owners Manual. If the rifle is in "Very Good" condition then it would be worth around $130