Welcome to the new Wizard Outboard Forum.
Working on a WD-4 - only missing pieces are the gas cap and grip.
http://store.oldmercs.com/product_p/36-23338a1.htm i think that this might fit IIRC
Cardiff torpedo grips in black are what you are looking for. Closest thing I've found to the original grip.
Doug Penn is another guy to try for parts. He may have a fuel cap and he carries grips. You want Mercury KD3, KD4 or Wizard WD3, WD4. cast aluminum tank caps.
I forgot about our own Joe Poole at Ferguson Poole Marine.
Joe has a lot of new old stock parts and may have a fuel cap.