I've got a Mud Duck MKII, sadly my first duck was 'shot' out of the sky by a radio malfunction. My Dad built both of them and I've often thought about installing floats on the big duck (120" span), but I'm afraid the paperboard probably isn't the best material for a float plane, especially if it were to flip or get blown over on the water. I have the giant inner-tube tires on the duck, perhaps I could find a floating "tailwheel" (like a 1/3rd scale inflatable tire) and just forget the floats altogether as it would be amphibious, like a real duck!
It appears that Mud Duck Aviation is trying to make a comeback (
http://www.mudduckaviation.com), but I haven't heard much about the revival or seen any ads, but their website has been updated as of April 2007. Sorry (and glad) to hear about the Cricket because I was thinking of building an electric version of one, but if it doesn't fly, I won't bother.
Thanks again for the comments about the Beaver. I've decided to go ahead and give it a try after I get it properly balanced. Possibly this weekend if it stops raining in Missouri and gives us a descent flying day. I don't believe the floats are too big, they were made by Sea Commander specifically for this airplane. They certainly cost enough that they ought to fly!!
I'll let you all know how it turns out, with photos!