Those clips look similar others I have seen on several types of lights.  You might take one to your autoparts on the perchance of finding one in a currently available light.  If that doesn't pan out, maybe make one from a spring grade wire.  Buy a throttle return spring that has the long straight end.  Use the end wire to make your new clip using the old one as a pattern. 

On Wed, Sep 2, 2020 at 5:05 PM Mike S <miso7@...> wrote:

The previous owner had painted the left rear tailight body color.  He also added a light on the passenger side, but left it black.  This has always bugged me & I decided to paint the left one black.  Unfortunately, as I was taking it apart, one of the spring clips that holds the glass lens in place popped out & flew to who knows where in the shop.

Anyone have a crapped out light that would be willing to sell me a clip?  
thanks,
Mike S