RE: Scale olde non-lead sled
No doubt there are a tremendus amount of old timer plans "out there". As in the just mentioned case these are in storage and next to impossible to aquire. Then when you do get a copy you will find that these are not designed for the loads todays winches and some hi-starts can put on them. Even some of todays glider designs are not designed properly. (see other recent and current threads)
Sometimes it takes a considerable amount of interal structure manipulation to get an old timer design flyable. Sometimes not. When the original is traced into a decent cad program you can scale it to most any size. It is from this scaled outline that the buildable internals are derived from.
I have a small box full of old timer plans copied from the 1930's and 1940's magazines that I plan on getting to -- one of these days. We even have one of the designers of some of these plans still flying at the park -- Chuck Hollinger. He even has the original hand drawings. Been working on him to have these xeroxed.