You'll need to compare the transom height and see if adapting the Sunfish gudgeon bracket will work in the height a Scorpion has. If the bracket will fit the transom, the Sunfish rudder should be an option.
If the change is do-able, follow the Sunfish instructions for upgrading from the old style to the new style rudder to install the bracket on your Scorpion.
Historical Parts Diagram. The parts shown in this list are no longer available.
I just measured the gudgeon dimension on my scorpion 4-3/16. The other issue could be the clearance above the bracket. It looks like there is only 5/16 clearance between the top of the bracket and the bottom of the deck trim.