How is it comming on the size-up. In order to get an idea about what size parts material to use, you may want to get your hands on some manuals of similar planes in the size category you want to build the Buttercup to. This may give you an idea of what size the parts should be (ie. 1/4 balsa or 1/8 ply ribs with caps, spar size and so on). Maybe some of the lager Telemasters or even the Flyin' Kings may help. Just some ideas...... keep us posted if you begin to build and what you decide to try. It may be interesting to see if that design can hanlde such a large size. May take some work to get the details worked out to build it as such a large model which is safe!