Sterling Engineering Co. Ltd. or Sterling Armaments Company. They were the same company that was renamed.
Sterling has not been heard from in may years and is presumed to have gone out of business.
Proprietary information
Sterling Arms Corp of Gasport NY made the Model 283 Target 300 pistol in 1970-71. The 300L (light barrel) was made the same years.
50-160
50-150 or so
The Sterling, which has been out of production for approximately 30 years, was an inexpensive pistol. It's value is minimal, in the area of $50 for one in excellent/working condition.
I just bought a magazine for my Sterling Arms 285 Husky .22 LR pistol from Gunclip website. gun show, gun shop, want ads
Assuming you mean a Sterling mdl 287 PPL in cal. .380, these retailed new for about $90.
Try e-gunparts.com
try egunparts
Ask a gunsmith for help
Best left to a gunsmith
Best left to a gun smith