Thanks for writing. We make rectifiers to fit early Hondas, and will be glad to make one to fit yours. Since there are variances in the early rectifiers, we need your help to get it right.
As many wiring diagrams as I have, including an exceptional scan of an original C100-C102-C105 owner’s manual, only the C100 and C102 have a wiring diagram. The C100 has a 2-wire rectifier, and the C102 a full wave rectifier with 3 wires (a 4th connection is the ground bolt).
Your original rectifier probably has wires attached with ring terminals. The full wave devices may have a Dark Brown wire and a Yellow wire as AC power inputs, then a Red wire to the battery + connection. Typically there was no wire to ground, just the bolts holding the rectifier provided the ground connection.