I didn't fix anything for i855GME, I got the 7.0.2/7.0.3-rc1 and
manually got the missing files and put in corresponding directories.
Do you get the glxproto.h ?
Did you installed drm-2.3.0 ?
Did you installed libpci-0.9.1
Is your /usr/local/include clean? Do you have the pkgconfig directory
in include folder?
Did you export LD_RUN_PATH=/usr/local/lib ?