Opened-end 3/4 model "S&P.M.S."

[webminister]

I found another old item in my father in laws tools... It's a heavy opened-end wrench 3/4" both ends, about 9" long, and it includes the inscription of "S&P.M.S" (see attached pics). Does anyone identify the maker of this wrench or what the letters mean?

 

[Provincial]

No photos.