Long ago I came across an article in an aviation magazine
describing (and having photos of) a set of "retractable" floats on a
Cub. These were pivoted on fore-and-aft pins at the mains so that they
swung outward far enough to give the wheel (which was still there and
fit into a well in the float when the float was down) access to the
surface. There were various cables and struts to make the things work.
They had small tailwheels on them to keep the tips of the ground. The
whole setup seemed to work fine.
Wish I knew where I could find that article.

Dan