Foremost IS the company that made the iron on hinge, you might try contacting the company or trying to find the hinges in a hobby shop, they may still have a pack in one of the older shops. I have used these hinges often, granted they don't look the best but at 30ft who can see them.
Another way that is simular to the foremost hinge is to cut 4 strips of fiber packing tape about 1 " long. Take 2 of these strips and put them togeather by overlapping the glue sides about 1/2 " then slide them into the elevator slot until the overlap is at the hinge line. Then press the tape down top and bottom. Now do the same thing with the other set but this time alternate the tape (top and bottom of the elevator) so it makes a hinge like the old u controlers used. Make sure you clean the surfaces good they probably have fuel on them.
You should really enjoy the Ready on floats I know I have for about 7 years, it was my first venture with floats. ENJOY !!!

PS after hinging this way I always lightly coat the hinge surface with CA, then you can use a paint pen or marker to sort of cover it up.