This was the EXACT information I needed to know! - Thank you.
Now to find a Sugino crank arm, though the link you provided for a Sugino MS looks close.
Will post more pictures of what the crank set looks like shortly. The arms do have Sugino's logo on them with no colored lettering.
Here is a picture of the arms with the Sugino logo I have.
Looking for a replacement left crank arm with this logo. Crank I have is a Sugino No 5 FE-WB from 1982
Would be VERY MUCH appreciated if someone can do a search with me to help me find these crank arms. Will buy a crank arm set if needed (within reason) to match the one I have.