why did Steve Howe use an EDS-1275 for Starship trooper in 1973?

He usally uses his ES-175

http://en.wikipedia.org/wiki/File:Gibson_ES-175_jl.png

But he used a EDS-1275 (double neck)

http://en.wikipedia.org/wiki/File:Gibson_EDS1275.jpg

why does he not play that more often