These black hard plastic bumpers are exactly what was on Gray and Automatic Electric 3 slot  payphone switch hooks . They are 100 percent the same in every way . They will fit Western Electric candlestick switch hooks too. 

 They work well . I see people using white  plastic screws etc . You do not  need to anymore . These are the best and closet to original you will find.

You get 1 for $5.19