Thread revival alert... stringing my 325/12 this morning and needed the proper gauges. Sure enough, the forum comes through once again. Thanks everyone! Cheers, JD
And I believe, to answer re: "why 12's on short scale and 10's on full scale?", that it is to keep string tension uniform/acceptable. This is a function of string size (gauge), scale length, and pitch. Here's some neat info I just googled:
http://www.noyceguitars.com/Technotes/Articles/T3.html
Imagine a 360/12 with a .010 tuned to E. Ordinary, normal, right? Now put a capo on the 3rd fret. Same string(.010), less scale length(due to capo), same tension(we didn't touch the tuning machines), higher pitch(G).
Now imagine that capo is the nut on a 325/12. It would be sounding a G with the combination of .010, short scale, regular uniform tension. Thicken the string(.012), and your pitch will go down to the standard E tuning on short scale at uniform tension.
I think that's right. Coffee and cigarettes this early make math hard.