Either the MA5C Individual Combat Weapon System (Assault Rifle) or the BR55HB SR Battle Rifle (Battle Rifle)
50-200 USD or so depending on condition.
No, since the Maruzen upgrades work only with bolt-action and GAS-assisted SR's.
Need to know what model, action type and caliber.
The SAR-21 is the current standard, but the SAR-80 and SR-88/SR-88A are still not fully phased out of service yet.
Made for Sears by Savage as their model M521.
Lockheed SR-71 Blackbird was used mainly for reconnaissance.
Unknown
Try egunparts dot com
No published sn data
If you are asking about the savage model 22?Then this .22cal rifle was made in 1922 only.
The SR 71 Blackbird was used as a reconnaissance aircraft which was operated at high speeds and altitudes to allow it to outrace threats