Mercury made motors for Western Auto under Wizard
brand name until late 1950's, Oliver (formerly
Chris Craft),then McCulloch (fomerly Scott Atwater)
and later Chrysler (formerly West Bend) supplied
motors to Western Auto under Wizard brand (per Mr.
Hunn's Old Outboard Book.
The model number seems like the Chrysler series...
Chrysler was forced to sell off outboard unit as
requirement of 1980's federal bail out loan...
became Force then became Mercury Mariner...first
place to try for parts is your Mercury Dealer.