WSAM stands for Worlds smallest Air Museum--It's an invention of Chip Fyn's--the idea is to scale all the models identically at 1/60 if you wanted to build a miniature exposition. Since some of his planes would be pretty tiny at 1/60, and he likes to fill the page, this gives the modeler a percentage by which ot scale up or down the model to meet this standard. My A7 and F100 were both at about 1/60, while the A4 is about 1/48. the forthcoming P-80 and T33 is also at 1/48. I, too prefer modeling at 1/72, BTW, but FG wants the models to generally fill two pages as tightly as possible. The regular sized FG model of the A4 is close to 1/72, but the grain of the paper runs the wrong way. I recommend reducing the large size to retain paper grain orientation. Makes it a lot easier to get nice curves, sharp creases, and such.
The F-100F I put in the spare parts section is 1/72.