stairway, standard tuning or alternate?

["Frank S. Corotto" <fcorotto@xxxxxxxxxxxxxxxxxxxxxxx>]

Mark Brown suggested that Stairway in TSRTS was in a different key.  
I don't know (I can't check at work) but watching it I always 
wondered if it was in an alternate tuning.  The tabs I have seen were 
always in standard tuning but in TSRTS Page plays it on his famous 
double-neck which he also uses for the Rain Song.  The Rain Song 
requires an alternate tuning (I forget what it is, it is one Page is 
well-known for using).  So my question is, was the original studio 
version of StH recorded in standard tuning and then Page figured out 
how to play it in the alternate tuning so he could use the same 
guitar for the Rain Song?  Or was the studio version recorded in the 
alternate tuning?  Or did Page play it live in standard tuning but 
use finger positions that look weird?

Forgive me if this has already been addressed.  I am relatively new 
to the list.

Frank