The 1970 front is identical to the Topps card...
but the back isn't.
You can see how OPC used the blue box only for the player's personal information. The write up was with a white background. My guess is that was done due to the smaller font necessary to get both the English and French text included. I do like that the cartoon has the words written by the cartoonist. They did drop the little speech bubble; not enough room for dual language, I suppose.
The 1971 card again has an identical front.
The back, though, has more differences than any other OPC set.
Pretty much the entire design was changed. That was quite a bit of work for OPC to make all those changes. Probably more than they wanted, since no back was ever so different again.
These cards bring my Billy OPC total to four, with three more left to go.